diff --git a/src/main/java/org/ntlab/amaryllis/server/entities/Category.java b/src/main/java/org/ntlab/amaryllis/server/entities/Category.java
index da3fd6f..5995619 100644
--- a/src/main/java/org/ntlab/amaryllis/server/entities/Category.java
+++ b/src/main/java/org/ntlab/amaryllis/server/entities/Category.java
@@ -1,10 +1,15 @@
 package org.ntlab.amaryllis.server.entities;
 
+import com.fasterxml.jackson.annotation.JsonIgnore;
+
+import java.util.ArrayList;
+
 import static java.util.UUID.randomUUID;
 
 public class Category {
-    String categoryId;
-    String categoryName;
+    private String categoryId;
+    private String categoryName;
+    private ArrayList<String> categorylist = new ArrayList<>();//そのcategoryが登録されているvidのリスト
 
     public Category(String categoryName) {
         this.categoryId = randomUUID().toString();
@@ -17,5 +22,19 @@
     public String getCategoryName() {
         return categoryName;
     }
+    public ArrayList<String> getCategorylist() {
+        return categorylist;
+    }
+    public void addCategorylist(String vid) {
+        for (String a : categorylist) {
+            if (a.equals(vid)) {
+                return;
+            }
+            this.categorylist.add(vid);
+        }
+    }
+    public void removeCategorylist(String vid) {
+        categorylist.remove(vid);
+    }
 
 }
\ No newline at end of file
diff --git a/src/main/java/org/ntlab/amaryllis/server/models/Categories.java b/src/main/java/org/ntlab/amaryllis/server/models/Categories.java
index 67df834..baf6d2d 100644
--- a/src/main/java/org/ntlab/amaryllis/server/models/Categories.java
+++ b/src/main/java/org/ntlab/amaryllis/server/models/Categories.java
@@ -6,7 +6,7 @@
 
 public class Categories {
     private static org.ntlab.amaryllis.server.models.Categories theInstance = null;
-    private static ArrayList<Category> Categories = new ArrayList<>();
+    private static ArrayList<Category> categories = new ArrayList<>();
 
     private Categories() {
         createCategory("旅行");
@@ -21,9 +21,18 @@
         return theInstance;
     }
 
+    public Category getCategory(String categoryId){
+        for (Category a : categories) {
+            if (a.getCategoryId().equals(categoryId)) {
+                return a;
+            }
+        }
+        return null;
+    }
+
     public Category createCategory(String categoryName) {
         Category newCategory = new Category(categoryName);
-        Categories.add(newCategory);
+        categories.add(newCategory);
         return newCategory;
     }
 
diff --git a/src/main/java/org/ntlab/amaryllis/server/resources/CategoriesRest.java b/src/main/java/org/ntlab/amaryllis/server/resources/CategoriesRest.java
index d91ea06..c5a809b 100644
--- a/src/main/java/org/ntlab/amaryllis/server/resources/CategoriesRest.java
+++ b/src/main/java/org/ntlab/amaryllis/server/resources/CategoriesRest.java
@@ -1,9 +1,11 @@
 package org.ntlab.amaryllis.server.resources;
 
+import org.ntlab.amaryllis.server.entities.Category;
 import org.ntlab.amaryllis.server.models.Categories;
 import org.springframework.stereotype.Component;
 import javax.ws.rs.*;
 import javax.ws.rs.core.MediaType;
+import java.util.ArrayList;
 
 @Component
 @Path("/categories")
@@ -17,3 +19,5 @@
     }
 
 }
+
+