diff --git a/f8/jsonlog.cc b/f8/jsonlog.cc
new file mode 100644
index 0000000..61e08eb
--- /dev/null
+++ b/f8/jsonlog.cc
@@ -0,0 +1,133 @@
+#include <thread>
+#include <mutex>
+#include <condition_variable>
+
+#include <a8/a8.h>
+
+#include <f8/f8.h>
+#include <f8/jsonlog.h>
+
+namespace f8
+{
+    struct JsonLogMsgNode
+    {
+        a8::XObject* xobj = nullptr;
+        JsonLogMsgNode* next = nullptr;
+    };
+
+    struct JsonLogImpl
+    {
+        std::string log_filename;
+
+        std::thread* save_thread = nullptr;
+        bool save_thread_shutdown = false;
+
+        std::mutex msg_mutex;
+        JsonLogMsgNode* top_node = nullptr;
+        JsonLogMsgNode* bot_node = nullptr;
+        JsonLogMsgNode* work_node = nullptr;
+        std::mutex *save_cond_mutex = nullptr;
+        std::condition_variable *save_cond = nullptr;
+    };
+
+    JsonLog::JsonLog()
+    {
+        impl_ = new JsonLogImpl();
+        impl_->save_cond_mutex = new std::mutex();
+        impl_->save_cond = new std::condition_variable();
+
+        impl_->top_node = nullptr;
+        impl_->bot_node = nullptr;
+        impl_->work_node = nullptr;
+    }
+
+    JsonLog::~JsonLog()
+    {
+        delete impl_->save_cond_mutex;
+        impl_->save_cond_mutex = nullptr;
+        delete impl_->save_cond;
+        impl_->save_cond = nullptr;
+        delete impl_;
+        impl_ = nullptr;
+    }
+
+    void JsonLog::Init()
+    {
+        impl_->save_thread_shutdown = false;
+        impl_->save_thread = new std::thread(&JsonLog::SaveToFileThreadProc, this);
+    }
+
+    void JsonLog::UnInit()
+    {
+        impl_->save_thread_shutdown = true;
+        impl_->save_thread->join();
+        delete impl_->save_thread;
+        impl_->save_thread = nullptr;
+    }
+
+    void JsonLog::SetLogFileName(const std::string& filename)
+    {
+        impl_->log_filename = filename;
+    }
+
+    void JsonLog::AddLog(a8::XObject* xobj)
+    {
+        JsonLogMsgNode *p = new JsonLogMsgNode();
+        p->xobj = xobj;
+        impl_->msg_mutex.lock();
+        if (impl_->bot_node) {
+            impl_->bot_node->next = p;
+            impl_->bot_node = p;
+        } else {
+            impl_->top_node = p;
+            impl_->bot_node = p;
+        }
+        impl_->msg_mutex.unlock();
+        {
+            std::unique_lock<std::mutex> lk(*impl_->save_cond_mutex);
+            impl_->save_cond->notify_all();
+        }
+    }
+
+    void JsonLog::SaveToFileThreadProc()
+    {
+        while (!impl_->save_thread_shutdown) {
+            if (!impl_->work_node && impl_->top_node) {
+                impl_->msg_mutex.lock();
+                impl_->work_node = impl_->top_node;
+                impl_->top_node = nullptr;
+                impl_->bot_node = nullptr;
+                impl_->msg_mutex.unlock();
+            }
+
+            if (impl_->work_node) {
+                time_t nowtime = time(nullptr);
+                struct tm tm_nowtime = {0};
+                localtime_r(&nowtime, &tm_nowtime);
+
+                char szfilename[256];
+                strftime(szfilename, a8::ArraySize(szfilename), impl_->log_filename.c_str(), &tm_nowtime);
+                std::string filename((char*)szfilename);
+                FILE *logfile = fopen(filename.c_str(), "a+");
+                if (logfile) {
+                    while (impl_->work_node) {
+                        JsonLogMsgNode *nextnode = impl_->work_node->next;
+                        std::string logmsg;
+                        impl_->work_node->xobj->ToJsonStr(logmsg);
+                        logmsg.push_back('\n');
+                        fwrite(logmsg.c_str(), 1, logmsg.size(), logfile);
+                        delete impl_->work_node->xobj;
+                        delete impl_->work_node;
+                        impl_->work_node = nextnode;
+                    }
+                    fclose(logfile);
+                }
+            }
+            {
+                std::unique_lock<std::mutex> lk(*impl_->save_cond_mutex);
+                impl_->save_cond->wait_for(lk, std::chrono::seconds(10));
+            }
+        }
+    }
+
+}
diff --git a/f8/jsonlog.h b/f8/jsonlog.h
new file mode 100644
index 0000000..30e51f6
--- /dev/null
+++ b/f8/jsonlog.h
@@ -0,0 +1,31 @@
+#pragma once
+
+#include <a8/singleton.h>
+
+namespace f8
+{
+
+    class JsonLog : public a8::Singleton<JsonLog>
+    {
+    private:
+        JsonLog();
+        friend class a8::Singleton<JsonLog>;
+
+    public:
+        ~JsonLog();
+
+        void Init();
+        void UnInit();
+
+        void SetLogFileName(const std::string& filename);
+
+        void AddLog(a8::XObject* logobj);
+
+    private:
+        void SaveToFileThreadProc();
+
+    private:
+        struct JsonLogImpl* impl_ = nullptr;
+    };
+
+}