diff --git a/internal/watcher/health/monitor/last_seen.go b/internal/watcher/health/monitor/last_seen.go
new file mode 100644
index 0000000..36e7ceb
--- /dev/null
+++ b/internal/watcher/health/monitor/last_seen.go
@@ -0,0 +1,22 @@
+package monitor
+
+import (
+	"time"
+
+	F "github.com/yusing/go-proxy/internal/utils/functional"
+)
+
+var lastSeenMap = F.NewMapOf[string, time.Time]()
+
+func SetLastSeen(service string, lastSeen time.Time) {
+	lastSeenMap.Store(service, lastSeen)
+}
+
+func UpdateLastSeen(service string) {
+	SetLastSeen(service, time.Now())
+}
+
+func GetLastSeen(service string) time.Time {
+	lastSeen, _ := lastSeenMap.Load(service)
+	return lastSeen
+}
diff --git a/internal/watcher/health/monitor/monitor.go b/internal/watcher/health/monitor/monitor.go
index c23a476..25d710e 100644
--- a/internal/watcher/health/monitor/monitor.go
+++ b/internal/watcher/health/monitor/monitor.go
@@ -27,7 +27,6 @@ type (
 
 		status     atomic.Value[health.Status]
 		lastResult *health.HealthCheckResult
-		lastSeen   time.Time
 
 		checkHealth HealthCheckFunc
 		startTime   time.Time
@@ -164,7 +163,7 @@ func (mon *monitor) MarshalJSON() ([]byte, error) {
 		Started:  mon.startTime,
 		Uptime:   mon.Uptime(),
 		Latency:  res.Latency,
-		LastSeen: mon.lastSeen,
+		LastSeen: GetLastSeen(mon.service),
 		Detail:   res.Detail,
 		URL:      mon.url.Load(),
 	}).MarshalJSON()
@@ -186,14 +185,17 @@ func (mon *monitor) checkUpdateHealth() error {
 	var status health.Status
 	if result.Healthy {
 		status = health.StatusHealthy
-		mon.lastSeen = time.Now()
+		UpdateLastSeen(mon.service)
 	} else {
 		status = health.StatusUnhealthy
 	}
 	if result.Healthy != (mon.status.Swap(status) == health.StatusHealthy) {
 		extras := map[string]any{
 			"Service Name": mon.service,
-			"Last Seen":    strutils.FormatLastSeen(mon.lastSeen),
+			"Time":         strutils.FormatTime(time.Now()),
+		}
+		if !result.Healthy {
+			extras["Last Seen"] = strutils.FormatLastSeen(GetLastSeen(mon.service))
 		}
 		if !mon.url.Load().Nil() {
 			extras["Service URL"] = mon.url.Load().String()