diff --git a/app/modules/project/router.py b/app/modules/project/router.py
index 091c1c2..5924517 100644
--- a/app/modules/project/router.py
+++ b/app/modules/project/router.py
@@ -418,6 +418,7 @@ async def project_page(request: Request, project_id: int) -> HTMLResponse:
             "color": p.get("color") or "#4573d2",
             "start_date": p.get("start_date"),
             "due_date": p.get("due_date"),
+            "created_by": p.get("created_by") or "",
         })
         nav_projects.append({
             "id": p["id"],
diff --git a/app/modules/project/templates/project/index.html b/app/modules/project/templates/project/index.html
index dc44197..f5c1324 100644
--- a/app/modules/project/templates/project/index.html
+++ b/app/modules/project/templates/project/index.html
@@ -1,7 +1,7 @@
 {% extends "erp_base.html" %}
 
 {% block head_extra %}
-<link rel="stylesheet" href="/static/project.css?v=20260626a" />
+<link rel="stylesheet" href="/static/project.css?v=20260626b" />
 <link rel="stylesheet" href="/static/vendor/material-symbols/material-symbols.css" />
 {% endblock %}
 
@@ -167,5 +167,5 @@
 <script>
   window.PJ_COLORS = {{ ["#4573d2","#37a3a3","#62a420","#e8a33d","#e8384f","#aa62e3","#f06a6a","#5a6772"] | tojson }};
 </script>
-<script src="/static/project.js?v=20260626a" defer></script>
+<script src="/static/project.js?v=20260626b" defer></script>
 {% endblock %}
diff --git a/app/modules/project/templates/project/project.html b/app/modules/project/templates/project/project.html
index a993ed0..437c3a9 100644
--- a/app/modules/project/templates/project/project.html
+++ b/app/modules/project/templates/project/project.html
@@ -1,7 +1,7 @@
 {% extends "erp_base.html" %}
 
 {% block head_extra %}
-<link rel="stylesheet" href="/static/project.css?v=20260626a" />
+<link rel="stylesheet" href="/static/project.css?v=20260626b" />
 <!-- 구글 머티리얼 심볼(담당자 아이콘 등) — self-host -->
 <link rel="stylesheet" href="/static/vendor/material-symbols/material-symbols.css" />
 <!-- 타임라인 vis-timeline — self-host -->
@@ -37,7 +37,7 @@
           {% endif %}
         </div>
         {% if nav_projects %}
-        <ul class="pj-tree">
+        <ul class="pj-tree" id="pj-tree-root">
           {% for p in nav_projects %}
           <li class="pj-tree-li" data-id="{{ p.id }}">
             <div class="pj-tree-row {% if p.id == project.id %}is-active{% endif %}">
@@ -291,5 +291,5 @@
 </script>
 
 <script src="/static/vendor/vis-timeline/vis-timeline-graph2d.min.js"></script>
-<script src="/static/project.js?v=20260626a" defer></script>
+<script src="/static/project.js?v=20260626b" defer></script>
 {% endblock %}
diff --git a/app/static/project.js b/app/static/project.js
index 7687ce3..6ae8ff3 100644
--- a/app/static/project.js
+++ b/app/static/project.js
@@ -763,8 +763,9 @@
     }
 
     function refreshActiveView() {
-      // 모든 뷰 클라이언트 재렌더(달력 포함, 새로고침 없음).
+      // 모든 뷰 + 좌측 트리 클라이언트 재렌더(새로고침 없음).
       renderView(currentView);
+      if (typeof renderTree === "function") renderTree();
     }
 
     // ── 업무 모달 ──
@@ -978,6 +979,8 @@
         if (id) res = await api("PUT", "/project/api/tasks/" + id, payload);
         else res = await api("POST", "/project/api/projects/" + projectId + "/tasks", payload);
         mergeTask(res.task);
+        // 새 업무는 해당 프로젝트 트리를 펼쳐 바로 보이게.
+        if (!id) treeSaveOpen((res.task && res.task.project_id) || projectId, true);
         closeModal(taskModal);
         refreshActiveView();
       } catch (e) { alert("저장 실패: " + e.message); }
@@ -997,7 +1000,7 @@
       } catch (e) { alert("삭제 실패: " + e.message); }
     });
 
-    // ── 프로젝트 트리 (아사나식 접기/펼치기) ──
+    // ── 프로젝트 트리 (아사나식) — tasks 로부터 클라이언트 렌더(업무 추가 즉시 반영) ──
     function setTreeOpen(li, open) {
       const children = li.querySelector(":scope > .pj-tree-children");
       const caret = li.querySelector(":scope > .pj-tree-row > .pj-tree-caret");
@@ -1015,19 +1018,59 @@
       try { localStorage.setItem("pj_tree_open", JSON.stringify(Array.from(s))); } catch (_) {}
     }
 
-    document.querySelectorAll(".pj-tree-caret").forEach(function (caret) {
-      caret.addEventListener("click", function (e) {
-        e.preventDefault(); e.stopPropagation();
-        const li = caret.closest(".pj-tree-li");
-        const children = li.querySelector(":scope > .pj-tree-children");
-        const open = children.hidden;        // 현재 닫혀있으면 → 연다
-        setTreeOpen(li, open);
-        treeSaveOpen(li.dataset.id, open);
+    function treeTaskLi(t, pid) {
+      return '<li class="pj-tree-li pj-tree-task"><div class="pj-tree-row" style="--pj-indent: 1">' +
+        '<span class="pj-tree-caret-spacer"></span>' +
+        '<a class="pj-tree-link pj-tree-tasklink" href="/project/p/' + pid + '?task=' + t.id +
+        '" data-project="' + pid + '" data-task="' + t.id + '">' +
+        '<span class="pj-tree-icon material-symbols-outlined" style="color:' + (t.project_color || "#4573d2") + '">' +
+        (t.completed_at ? "task_alt" : "radio_button_unchecked") + "</span>" +
+        '<span class="pj-tree-name ' + (t.completed_at ? "pj-tree-done" : "") + '">' + escapeHtml(t.title || "") + "</span>" +
+        "</a></div></li>";
+    }
+    function treeProjLi(p) {
+      const ptasks = tasks.filter(function (t) { return t.project_id === p.id; });
+      const has = ptasks.length > 0;
+      const caret = has
+        ? '<button type="button" class="pj-tree-caret" aria-expanded="false" title="펼치기/접기"><span class="material-symbols-outlined">chevron_right</span></button>'
+        : '<span class="pj-tree-caret-spacer"></span>';
+      const del = isAdmin
+        ? '<span class="pj-tree-acts"><button type="button" class="pj-icon-btn pj-tree-del" data-id="' + p.id +
+          '" data-name="' + escapeHtml(p.name) + '" data-creator="' + escapeHtml(p.created_by || "") + '" title="프로젝트 삭제">×</button></span>'
+        : "";
+      let h = '<li class="pj-tree-li" data-id="' + p.id + '"><div class="pj-tree-row ' + (p.id === projectId ? "is-active" : "") + '">' +
+        caret + '<a class="pj-tree-link" href="/project/p/' + p.id + '">' +
+        '<span class="pj-tree-icon material-symbols-outlined" style="color:' + (p.color || "#4573d2") + '">folder</span>' +
+        '<span class="pj-tree-name">' + escapeHtml(p.name) + "</span></a>" + del + "</div>";
+      if (has) h += '<div class="pj-tree-children" hidden><ul class="pj-tree">' +
+        ptasks.map(function (t) { return treeTaskLi(t, p.id); }).join("") + "</ul></div>";
+      return h + "</li>";
+    }
+    function wireTreeHandlers(rootUl) {
+      rootUl.querySelectorAll(".pj-tree-caret").forEach(function (caret) {
+        caret.addEventListener("click", function (e) {
+          e.preventDefault(); e.stopPropagation();
+          const li = caret.closest(".pj-tree-li");
+          const children = li.querySelector(":scope > .pj-tree-children");
+          const open = children.hidden;
+          setTreeOpen(li, open);
+          treeSaveOpen(li.dataset.id, open);
+        });
       });
-    });
-
-    // 저장된 펼침 상태 복원 + 활성 프로젝트의 상위 자동 펼침
-    (function restoreTree() {
+      rootUl.querySelectorAll(".pj-tree-del").forEach(function (b) {
+        b.addEventListener("click", async function (e) {
+          e.preventDefault(); e.stopPropagation();
+          if (!canDelete(b.dataset.creator)) { alert(DELETE_DENIED); return; }
+          if (!confirm("'" + (b.dataset.name || "") + "' 프로젝트를 삭제할까요? 안의 업무도 모두 삭제됩니다.")) return;
+          try {
+            await api("DELETE", "/project/api/projects/" + b.dataset.id);
+            if (String(b.dataset.id) === String(projectId)) location.href = "/project/";
+            else location.reload();
+          } catch (err) { alert("삭제 실패: " + err.message); }
+        });
+      });
+    }
+    function restoreTreeState() {
       const openSet = treeOpenSet();
       document.querySelectorAll(".pj-tree-li").forEach(function (li) {
         if (openSet.has(String(li.dataset.id))) setTreeOpen(li, true);
@@ -1040,21 +1083,16 @@
         if (li) setTreeOpen(li, true);
         box = li ? (li.parentElement ? li.parentElement.closest(".pj-tree-children") : null) : null;
       }
-    })();
+    }
+    function renderTree() {
+      const rootUl = el("pj-tree-root");
+      if (!rootUl) return;
+      rootUl.innerHTML = projectsMeta.map(treeProjLi).join("");
+      wireTreeHandlers(rootUl);
+      restoreTreeState();
+    }
+    renderTree();
 
-    // 프로젝트 삭제 (트리)
-    document.querySelectorAll(".pj-tree-del").forEach(function (b) {
-      b.addEventListener("click", async function (e) {
-        e.preventDefault(); e.stopPropagation();
-        if (!canDelete(b.dataset.creator)) { alert(DELETE_DENIED); return; }
-        if (!confirm("'" + (b.dataset.name || "") + "' 프로젝트를 삭제할까요? 안의 업무도 모두 삭제됩니다.")) return;
-        try {
-          await api("DELETE", "/project/api/projects/" + b.dataset.id);
-          if (String(b.dataset.id) === String(projectId)) location.href = "/project/";
-          else location.reload();
-        } catch (err) { alert("삭제 실패: " + err.message); }
-      });
-    });
     // 새 최상위 프로젝트 (관리자)
     const newProjSide = el("pj-new-project-side");
     if (newProjSide) newProjSide.addEventListener("click", async function () {