diff --git a/config/rule_level.txt b/config/rule_level.txt
new file mode 100644
index 00000000..e69de29b
diff --git a/src/detections/configs.rs b/src/detections/configs.rs
index 9ad2185a..ef8e6d50 100644
--- a/src/detections/configs.rs
+++ b/src/detections/configs.rs
@@ -1,7 +1,7 @@
 use crate::detections::print::AlertMessage;
 use crate::detections::utils;
 use chrono::{DateTime, Utc};
-use clap::{App, AppSettings, ArgMatches};
+use clap::{App, Arg, AppSettings, ArgMatches};
 use hashbrown::HashMap;
 use hashbrown::HashSet;
 use lazy_static::lazy_static;
@@ -92,6 +92,10 @@ fn build_app<'a>() -> ArgMatches<'a> {
         .version("1.1.0")
         .author("Yamato Security (https://github.com/Yamato-Security/hayabusa)")
         .setting(AppSettings::VersionlessSubcommands)
+        .arg( // TODO: When update claps to 3.x, these can write in usage texts...
+            Arg::from_usage("--level-tuning=[RULE_LEVEL_FILE] 'Fix rule file's level'")
+                .default_value("./config/rule_level.txt")
+        )
         .usage(usages)
         .args_from_usage(usages)
         .get_matches()
diff --git a/src/main.rs b/src/main.rs
index 3461b1d9..a09bd0c0 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -104,6 +104,29 @@ impl App {
             println!();
             return;
         }
+
+        if configs::CONFIG
+            .read()
+            .unwrap()
+            .args.is_present("level-tuning")
+        {
+            if let Some(level_tuning_path) = configs::CONFIG.read().unwrap().args.value_of("level-tuning") {
+                if Path::new(level_tuning_path).exists() {
+                    println!("level-tuning file exist: {}", level_tuning_path);
+                    println!("WIP: level-tuning....");
+                } else {
+                    AlertMessage::alert(
+                        &mut BufWriter::new(std::io::stderr().lock()),
+                        &format!(
+                            "Need rule_levels.txt file to use --level-tuning option"
+                        ),
+                    )
+                    .ok();
+                    return;
+                }
+            }
+        }
+
         if !Path::new("./config").exists() {
             AlertMessage::alert(
                 &mut BufWriter::new(std::io::stderr().lock()),