All, I knew we can implement a draggable to a element just simply call the .draggable method in jquery ui.
here is an example for it including connect to sortable.
$(".draggable").draggable({
            helper : function(){
                   //return something dom.},
            cursor : 'move',
            connectToSortable : '.sortableLayoutSection'});
$(".sortableLayoutSection").sortable({
            appendTo : parent,
            containment : "parent",
            cursor : "pointer",
            placeholder : 'li-placeholder',
            forcePlaceholderSize : false
        });
But my question is how can I known the draggable item really drop into the specified container(in this example is element with class named .sortableLayoutSection)? thanks.
Updated
$(".sortableLayoutSection").sortable({
                appendTo : parent,
                containment : "parent",
                cursor : "pointer",
                placeholder : 'li-placeholder',
                forcePlaceholderSize : false,
                receive: function( event, ui ) {alert('ok.got something.')}
            });