Wei,

How many objects are you talking about using? If it's thousands or more you might consider using a lighterweight baseclass. There is a Wiki article showing the relative sizes of the different classes.
http://fox.wikis.com/wc.dll?Wiki~TestMemoryCreateDestroy~VFP

>Thanks, David. I'll look into that. I have a library with a set of classes I wrote a while back. In the classes I used the null assignment to release the child (subsequent) object. Now I use it in a new application and I run into some kind of memory related errors when running the new application to process a large size of data. I want to make sure whether the memory management in those old classes has flaws.