diff --git a/install.sh b/install.sh
index 1b30553..4d68bd7 100755
--- a/install.sh
+++ b/install.sh
@@ -40,6 +40,7 @@ service_name="komari-agent"
 target_dir="/opt/komari"
 github_proxy=""
 install_version="" # New parameter for specifying version
+need_vnstat=false # Flag to indicate if vnstat is needed
 
 # Detect OS
 os_type=$(uname -s)
@@ -82,6 +83,11 @@ while [[ $# -gt 0 ]]; do
             install_version="$2"
             shift 2
             ;;
+        --month-rotate)
+            need_vnstat=true
+            komari_args="$komari_args $1"
+            shift
+            ;;
         --install*)
             log_warning "Unknown install parameter: $1"
             shift
@@ -126,6 +132,11 @@ if [ -n "$install_version" ]; then
 else
     log_config "  Agent version: ${GREEN}Latest${NC}"
 fi
+if [ "$need_vnstat" = true ]; then
+    log_config "  vnstat installation: ${GREEN}Required (--month-rotate detected)${NC}"
+else
+    log_config "  vnstat installation: ${GREEN}Not required${NC}"
+fi
 echo ""
 
 # Function to uninstall the previous installation
@@ -221,9 +232,69 @@ install_dependencies() {
     fi
 }
 
+# Function to install vnstat if needed
+install_vnstat() {
+    if [ "$need_vnstat" = true ]; then
+        log_step "Checking and installing vnstat for --month-rotate functionality..."
+        
+        if command -v vnstat >/dev/null 2>&1; then
+            log_success "vnstat is already installed"
+            return
+        fi
+        
+        log_info "vnstat not found, installing..."
+        
+        # Install vnstat based on package manager
+        if command -v apt >/dev/null 2>&1; then
+            log_info "Using apt to install vnstat..."
+            apt update
+            apt install -y vnstat
+        elif command -v yum >/dev/null 2>&1; then
+            log_info "Using yum to install vnstat..."
+            yum install -y vnstat
+        elif command -v dnf >/dev/null 2>&1; then
+            log_info "Using dnf to install vnstat..."
+            dnf install -y vnstat
+        elif command -v apk >/dev/null 2>&1; then
+            log_info "Using apk to install vnstat..."
+            apk add vnstat
+        elif command -v brew >/dev/null 2>&1; then
+            log_info "Using Homebrew to install vnstat..."
+            brew install vnstat
+        elif command -v pacman >/dev/null 2>&1; then
+            log_info "Using pacman to install vnstat..."
+            pacman -S --noconfirm vnstat
+        else
+            log_error "No supported package manager found for vnstat installation"
+            log_error "Please install vnstat manually to use --month-rotate functionality"
+            exit 1
+        fi
+        
+        # Verify installation
+        if command -v vnstat >/dev/null 2>&1; then
+            log_success "vnstat installed successfully"
+            
+            # Start vnstat daemon if systemd is available
+            if command -v systemctl >/dev/null 2>&1; then
+                log_info "Starting vnstat daemon..."
+                systemctl enable vnstat
+                systemctl start vnstat
+            elif [ "$os_name" = "darwin" ] && command -v launchctl >/dev/null 2>&1; then
+                log_info "vnstat daemon management varies on macOS, please check vnstat documentation"
+            fi
+        else
+            log_error "Failed to install vnstat"
+            exit 1
+        fi
+    fi
+}
+
 # Install dependencies
 install_dependencies
 
+# Install vnstat if needed for month-rotate
+install_vnstat
+
 arch=$(uname -m)
 case $arch in
     x86_64)