diff --git a/src/operations/SelectAllContent.ts b/src/operations/SelectAllContent.ts
index 971d7ba..587501a 100644
--- a/src/operations/SelectAllContent.ts
+++ b/src/operations/SelectAllContent.ts
@@ -48,13 +48,10 @@ export class SelectAllContent implements Operation {
     const list = root.getListUnderCursor();
     const contentStart = list.getFirstLineContentStartAfterCheckbox();
     const contentEnd = list.getLastLineContentEnd();
-
-    if (
-      selectionFrom.line < contentStart.line ||
-      selectionTo.line > contentEnd.line
-    ) {
-      return false;
-    }
+    const listUnderSelectionFrom = root.getListUnderLine(selectionFrom.line);
+    const listStart =
+      listUnderSelectionFrom.getFirstLineContentStartAfterCheckbox();
+    const listEnd = listUnderSelectionFrom.getContentEndIncludingChildren();
 
     this.stopPropagation = true;
     this.updated = true;
@@ -64,12 +61,37 @@ export class SelectAllContent implements Operation {
       selectionFrom.ch === contentStart.ch &&
       selectionTo.line === contentEnd.line &&
       selectionTo.ch === contentEnd.ch
+    ) {
+      if (list.getChildren().length) {
+        // select sub lists
+        root.replaceSelections([
+          { anchor: contentStart, head: list.getContentEndIncludingChildren() },
+        ]);
+      } else {
+        // select whole list
+        root.replaceSelections([{ anchor: rootStart, head: rootEnd }]);
+      }
+    } else if (
+      listStart.ch == selectionFrom.ch &&
+      listEnd.line == selectionTo.line &&
+      listEnd.ch == selectionTo.ch
     ) {
       // select whole list
       root.replaceSelections([{ anchor: rootStart, head: rootEnd }]);
-    } else {
+    } else if (
+      (selectionFrom.line > contentStart.line ||
+        (selectionFrom.line == contentStart.line &&
+          selectionFrom.ch >= contentStart.ch)) &&
+      (selectionTo.line < contentEnd.line ||
+        (selectionTo.line == contentEnd.line &&
+          selectionTo.ch <= contentEnd.ch))
+    ) {
       // select whole line
       root.replaceSelections([{ anchor: contentStart, head: contentEnd }]);
+    } else {
+      this.stopPropagation = false;
+      this.updated = false;
+      return false;
     }
 
     return true;
diff --git a/src/operations/__tests__/SelectAllContent.test.ts b/src/operations/__tests__/SelectAllContent.test.ts
new file mode 100644
index 0000000..0490d5e
--- /dev/null
+++ b/src/operations/__tests__/SelectAllContent.test.ts
@@ -0,0 +1,56 @@
+import { makeEditor, makeRoot, makeSettings } from "../../__mocks__";
+import { SelectAllContent } from "../SelectAllContent";
+
+test("when performed the first time, should select the whole line under cursor; when performed the second time, should select all sub-bullets of the cursor line if it is a parent-bullet", () => {
+  const root = makeRoot({
+    editor: makeEditor({
+      text: "- item 1\n- item 2\n    - item 2.1\n    - item 2.2\n- item 3\n",
+      cursor: { line: 1, ch: 2 },
+    }),
+    settings: makeSettings(),
+  });
+
+  const op = new SelectAllContent(root);
+
+  op.perform();
+  expect(root.getSelection().anchor.line).toBe(1);
+  expect(root.getSelection().anchor.ch).toBe(2);
+  expect(root.getSelection().head.line).toBe(1);
+  expect(root.getSelection().head.ch).toBe(8);
+
+  op.perform();
+  expect(root.getSelection().anchor.line).toBe(1);
+  expect(root.getSelection().anchor.ch).toBe(2);
+  expect(root.getSelection().head.ch).toBe(14);
+  expect(root.getSelection().head.line).toBe(3);
+
+  op.perform();
+  expect(root.getSelection().anchor.line).toBe(0);
+  expect(root.getSelection().anchor.ch).toBe(0);
+  expect(root.getSelection().head.line).toBe(4);
+  expect(root.getSelection().head.ch).toBe(8);
+});
+
+test("when a whole line is selected and the selected line has no sub-bullets, should select the whole list", () => {
+  const root = makeRoot({
+    editor: makeEditor({
+      text: "- item 1\n- item 2\n    - item 2.1\n    - item 2.2\n- item 3\n",
+      cursor: { line: 4, ch: 2 },
+    }),
+    settings: makeSettings(),
+  });
+
+  const op = new SelectAllContent(root);
+
+  op.perform();
+  expect(root.getSelection().anchor.line).toBe(4);
+  expect(root.getSelection().anchor.ch).toBe(2);
+  expect(root.getSelection().head.line).toBe(4);
+  expect(root.getSelection().head.ch).toBe(8);
+
+  op.perform();
+  expect(root.getSelection().anchor.line).toBe(0);
+  expect(root.getSelection().anchor.ch).toBe(0);
+  expect(root.getSelection().head.line).toBe(4);
+  expect(root.getSelection().head.ch).toBe(8);
+});