使用自定义助行器：

class WPSE_33175_Simple_Walker extends Walker
{
    public function walk( $elements, $max_depth )
    {
        $list = array ();

        foreach ( $elements as $item )
            $list[] = "<a href=\'$item->url\'>$item->title</a>";

        return join( "\\n", $list );
    }
}

wp_nav_menu(
    array (
        \'theme_location\' => \'your_registered_theme_location\',
        \'walker\'         => new WPSE_33175_Simple_Walker,
        \'items_wrap\'     => \'<nav>%3$s</nav>\'
    )
);