diff --git a/ckb-bench/src/main.rs b/ckb-bench/src/main.rs
index 8db801a..0c3ca99 100644
--- a/ckb-bench/src/main.rs
+++ b/ckb-bench/src/main.rs
@@ -283,20 +283,20 @@ pub fn entrypoint(clap_arg_match: ArgMatches<'static>) {
                 }
             }
 
-            let stat_time = t_bench.div(2);
+            let t_stat = t_bench.div(2);
             let fixed_tip_number = watcher.get_fixed_header().number();
-            let metrics = stat::stat(&nodes[0], zero_load_number, fixed_tip_number, stat_time);
-            ckb_testkit::info!("{:?}", metrics);
+            let metrics = stat::stat(&nodes[0], zero_load_number, fixed_tip_number, t_stat, Some(t_delay));
+            ckb_testkit::info!("metrics: {}", serde_json::json!(metrics));
         }
         ("stat", Some(arguments)) => {
             let rpc_urls = values_t_or_exit!(arguments, "rpc-urls", Url);
             let from_number = value_t_or_exit!(arguments, "from_number", BlockNumber);
             let to_number = value_t_or_exit!(arguments, "to_number", BlockNumber);
             let stat_time_ms = value_t_or_exit!(arguments, "stat_time_ms", u64);
-            let stat_time = Duration::from_millis(stat_time_ms);
+            let t_stat = Duration::from_millis(stat_time_ms);
             let node = Node::init_from_url(rpc_urls[0].as_str(), Default::default());
-            let metrics = stat::stat(&node, from_number, to_number, stat_time);
-            ckb_testkit::info!("{:?}", metrics);
+            let metrics = stat::stat(&node, from_number, to_number, t_stat, None);
+            ckb_testkit::info!("metrics: {}", serde_json::json!(metrics));
         }
         _ => {
             eprintln!("wrong usage");
diff --git a/ckb-bench/src/stat.rs b/ckb-bench/src/stat.rs
index 9f6ef23..2738c26 100644
--- a/ckb-bench/src/stat.rs
+++ b/ckb-bench/src/stat.rs
@@ -17,6 +17,7 @@ pub struct Metrics {
     pub n_nodes: usize,
     pub n_outputs: usize,
     pub ckb_version: String,
+    pub delay_time_ms: Option<u64>,
 }
 
 pub fn stat(
@@ -24,6 +25,7 @@ pub fn stat(
     from_number: BlockNumber,
     to_number: BlockNumber,
     stat_time: Duration,
+    delay_time: Option<Duration>,
 ) -> Metrics {
     assert_ne!(from_number, 0);
     assert!(from_number < to_number);
@@ -94,5 +96,6 @@ pub fn stat(
     best_metrics.ckb_version = local_node_info.version;
     best_metrics.n_nodes = local_node_info.connections.value() as usize + 1;
     best_metrics.n_outputs = n_outputs;
+    best_metrics.delay_time_ms = delay_time.map(|t| t.as_millis() as u64);
     best_metrics
 }