Hi Feng, > What is the problem? maybe the setting or other reason?? The problem is that the compiler does not know that iterator is a type. You need to specify that it is a type using the typename keyword. Note: the typename keyword is required in this kind of context, and cannot be used in contexts where it is not required. typename vector< vector<elemType> >::iterator collection_itor = src_collection.begin(); HTH, --Eljay
