diff --git a/README.md b/README.md
index 6760b14..3ef787e 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,28 @@
 # NSEMU
-NSEMU is Nintendo Switch Emulator. It allows you to play games on PC.
+NSEMU is a Nintendo Switch Emulator. It allows you to play games on PC.
+## Building
+```
+git clone https://github.com/RKX1209/nsemu.git
+cd nsemu
+make -j4
+```
+
+## Running
+```
+./nsemu <NSO file>
+```
+You can try some homebrew application like [libtransistor](https://github.com/reswitched/libtransistor).  
+
+```
+./nsemu /path/to/libtransistor/build/test/test_bsd.nso
+
+``` 
+
+## Debugging
+Currently you should modify a run level flag to debugging mode.  
+include/Util.hpp
+```cpp
+static RunLevel curlevel = RUN_LEVEL_DEBUG;
+//static RunLevel curlevel = RUN_LEVEL_RELEASE;
+```
+
diff --git a/include/Util.hpp b/include/Util.hpp
index 888e115..128fded 100644
--- a/include/Util.hpp
+++ b/include/Util.hpp
@@ -13,8 +13,8 @@ enum RunLevel {
 	RUN_LEVEL_DEBUG,
 };
 
-static RunLevel curlevel = RUN_LEVEL_DEBUG;
-//static RunLevel curlevel = RUN_LEVEL_RELEASE;
+//static RunLevel curlevel = RUN_LEVEL_DEBUG;
+static RunLevel curlevel = RUN_LEVEL_RELEASE;
 
 static void util_print(RunLevel level, FILE *fp, const char *format, ...) {
 	if (curlevel >= level) {