Change role name

function wps_change_role_name() {
  global $wp_roles;
  if ( ! isset( $wp_roles ) )
    $wp_roles = new WP_Roles();
    $wp_roles->roles['subscriber']['name'] = '會員';
    $wp_roles->role_names['subscriber'] = '會員';
  }
add_action('init', 'wps_change_role_name');