Number of item in cart at theme level I have to display number of item in cart/basket in design where I can't use the menu. So my question is...how to access number of item of cart at theme level?

Is there any function for template file which can return me this, so that I can show it in page.tpl.php ?
You can use commerce_cart_order_load() to load the order for the current user, and an EntityMetadataWrapper to extract the relevant field data, and commerce_line_items_quantity() to get at the actual quantities. e.g.

if ($order = commerce_cart_order_load($GLOBALS['user']-&gt;uid)) {
  $order_wrapper = entity_metadata_wrapper('commerce_order', $order);
  $quantity = commerce_line_items_quantity($order_wrapper-&gt;commerce_line_items);

  // Do something with $quantity...
}


This code can be used in a module or theme.