> I need a clarification on child::category. Does it returns 
> all child category elements of current element?

Yes.

> If my structure is
> <category>
>     <list>
>         <category>
>         </category>
>     </list
> </category>
> 
> so will it return inner category element?

Yes, if the current element is "list".

Michael Kay
http://www.saxonica.com/