cuong_nguyentuan wrote: i'm using dynamic assembly at runtime, but i want to change it at the runtime by overwrite on it. Then why save it to disk? Why not keep in memory? Anyways to get the type unloaded you will have to unload the appdomain. My PluginManager article mite be of use. http://www.codeproject.com/useritems/PluginManager.asp[^] Cheers :) I rated this article 2 by mistake. It deserves more. I wanted to get to the second page... - vjedlicka 3:33 25 Nov '02