diff --git a/src/index.ts b/src/index.ts
index faab110..6c6008b 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -38,6 +38,7 @@ const main = async () => {
 		members: number[];
 		remarks: string[];
 		include: string[];
+		isChanged?: boolean;
 	}[] = [];
 
 	console.log("INFO: start AS-SETS generation.");
@@ -45,13 +46,13 @@ const main = async () => {
 	let i = 1;
 
 	for (let asSetName in config["AS-SETS"]) {
+		let isChanged = true;
 		console.log(
-			`INFO: generating AS-SETS <${asSetName}>... (${i}/${
-				Object.keys(config["AS-SETS"]).length
+			`INFO: generating AS-SETS <${asSetName}>... (${i}/${Object.keys(config["AS-SETS"]).length
 			})\n`
 		);
 
-		let members = await Promise.all(
+		let members = ([...new Set((await Promise.all(
 			config.members.map(async (member) => {
 				const setName = Object.keys(member)[0];
 				const setGroup = Object.values(member)[0];
@@ -80,7 +81,13 @@ const main = async () => {
 
 				return asnList;
 			})
-		);
+		)).flat(Infinity))].filter(Boolean) as any).sort((a: number, b: number) => a - b);
+
+		console.log(JSON.stringify(members), JSON.stringify(await bgpq4(asSetName)));
+		if (JSON.stringify(members) === JSON.stringify(await bgpq4(asSetName))) {
+			console.log(`[INFO] AS-SET <${asSetName}> is not changed.`);
+			isChanged = false;
+		}
 
 		config["AS-SETS"][asSetName].remarks.push(
 			`Generated by git.186526.xyz/186526/net186-as-set.`
@@ -100,29 +107,32 @@ const main = async () => {
 			remarks: config["AS-SETS"][asSetName].remarks,
 			members: [...new Set(members.flat(Infinity))].filter(Boolean) as any,
 			include: (config["AS-SETS"][asSetName].include ?? []).sort(),
+			isChanged: isChanged,
 		});
 		i++;
 		console.log("");
 	}
 	const answer = await Promise.all(
 		asSets.map(
-			async (k) =>
+			async (k) => {
+				if (!k.isChanged) return "";
+				return `
+				as-set: ${k["AS-SET"]}
+				${k["MNT-BY"].map((k) => `mnt-by: ${k}`).join("\n")}
+				${k["TECH-C"].map((k) => `tech-c: ${k}`).join("\n")}
+				${k["ADMIN-C"].map((k) => `admin-c: ${k}`).join("\n")}
+				${k.remarks.map((k) => `remarks: ${k}`).join("\n")}
+				${(
+						await Promise.all(
+							k.members.map(
+								async (k) =>
+									`remarks: ${await getNetName(k)} from ${cache.get(k)}\nmembers: AS${k}`
+							)
+						)
+					).join("\n")}${k.include.map((k) => `\nmembers: ${k}`)}
+				source: RIPE\npassword: ${env["RIPE_PASSWORD"]}\n
 				`
-as-set: ${k["AS-SET"]}
-${k["MNT-BY"].map((k) => `mnt-by: ${k}`).join("\n")}
-${k["TECH-C"].map((k) => `tech-c: ${k}`).join("\n")}
-${k["ADMIN-C"].map((k) => `admin-c: ${k}`).join("\n")}
-${k.remarks.map((k) => `remarks: ${k}`).join("\n")}
-${(
-	await Promise.all(
-		k.members.map(
-			async (k) =>
-				`remarks: ${await getNetName(k)} from ${cache.get(k)}\nmembers: AS${k}`
-		)
-	)
-).join("\n")}${k.include.map((k) => `\nmembers: ${k}`)}
-source: RIPE\npassword: ${env["RIPE_PASSWORD"]}\n
-`
+			}
 		)
 	);
 	console.log("INFO: sending update to RIPE Syncupdates...");