diff --git a/app/src/main/java/org/ntlab/acanthus_client/views/paint/page/PageActivity.java b/app/src/main/java/org/ntlab/acanthus_client/views/paint/page/PageActivity.java
index 52f50d2..20ed231 100644
--- a/app/src/main/java/org/ntlab/acanthus_client/views/paint/page/PageActivity.java
+++ b/app/src/main/java/org/ntlab/acanthus_client/views/paint/page/PageActivity.java
@@ -136,6 +136,7 @@
     //-----------------------------------------------------------------
     //
     private void startObserve() {
+        // ページの現在の番号
         pageViewModel.getCurPageNo().observe(this, new Observer<Integer>() {
             @Override
             public void onChanged(Integer pageNo) {
@@ -145,6 +146,7 @@
             }
         });
 
+        // ページのサムネ更新
         pageViewModel.getPages().observe(this, new Observer<HashMap<Integer, String>>() {
             @Override
             public void onChanged(HashMap<Integer, String> s) {
@@ -154,6 +156,14 @@
                 Log.d("a", "onFailure: -----------------------OK:Obs");
             }
         });
+
+        // ページのサイズ更新
+        pageViewModel.getPageSize().observe(this, new Observer<Integer>() {
+            @Override
+            public void onChanged(Integer pageSize) {
+                binding.textPageSize.setText("/" + pageSize.toString());
+            }
+        });
     }
     //-----------------------------------------------------------------
 }
\ No newline at end of file