diff --git a/package.json b/package.json
index a2896f4c7..ae959d1b1 100644
--- a/package.json
+++ b/package.json
@@ -97,6 +97,7 @@
     "accesses": "2.5.0",
     "animejs": "2.0.2",
     "autwh": "0.0.1",
+    "bayes": "0.0.7",
     "bcryptjs": "2.4.3",
     "body-parser": "1.17.2",
     "cafy": "2.4.0",
@@ -120,6 +121,7 @@
     "is-root": "1.0.0",
     "is-url": "1.2.2",
     "js-yaml": "3.9.1",
+    "mecab-async": "^0.1.0",
     "mongodb": "2.2.31",
     "monk": "6.0.3",
     "morgan": "1.8.2",
diff --git a/src/tools/ai/categorizer.ts b/src/tools/ai/categorizer.ts
new file mode 100644
index 000000000..f70ce1b7d
--- /dev/null
+++ b/src/tools/ai/categorizer.ts
@@ -0,0 +1,89 @@
+import * as fs from 'fs';
+const bayes = require('bayes');
+const MeCab = require('mecab-async');
+import Post from '../../api/models/post';
+
+export default class Categorizer {
+	classifier: any;
+	categorizerDbFilePath: string;
+	mecab: any;
+
+	constructor(categorizerDbFilePath: string, mecabCommand: string = 'mecab -d /usr/share/mecab/dic/mecab-ipadic-neologd') {
+		this.categorizerDbFilePath = categorizerDbFilePath;
+
+		this.mecab = new MeCab();
+		this.mecab.command = mecabCommand;
+
+		// BIND -----------------------------------
+		this.tokenizer = this.tokenizer.bind(this);
+	}
+
+	tokenizer(text: string) {
+		return this.mecab.wakachiSync(text);
+	}
+
+	async init() {
+		try {
+			const db = fs.readFileSync(this.categorizerDbFilePath, {
+				encoding: 'utf8'
+			});
+
+			this.classifier = bayes.fromJson(db);
+			this.classifier.tokenizer = this.tokenizer;
+		} catch(e) {
+			this.classifier = bayes({
+				tokenizer: this.tokenizer
+			});
+
+			// 訓練データ
+			const verifiedPosts = await Post.find({
+				is_category_verified: true
+			});
+
+			// 学習
+			verifiedPosts.forEach(post => {
+				this.classifier.learn(post.text, post.category);
+			});
+
+			this.save();
+		}
+	}
+
+	async learn(id, category) {
+		const post = await Post.findOne({ _id: id });
+
+		Post.update({ _id: id }, {
+			$set: {
+				category: category,
+				is_category_verified: true
+			}
+		});
+
+		this.classifier.learn(post.text, category);
+
+		this.save();
+	}
+
+	async categorize(id) {
+		const post = await Post.findOne({ _id: id });
+
+		const category = this.classifier.categorize(post.text);
+
+		Post.update({ _id: id }, {
+			$set: {
+				category: category
+			}
+		});
+	}
+
+	async test(text) {
+		return this.classifier.categorize(text);
+	}
+
+	save() {
+		fs.writeFileSync(this.categorizerDbFilePath, this.classifier.toJson(), {
+			encoding: 'utf8'
+		});
+	}
+}
+