Hi Wayne,Thanks for the reply. I was planning to use it as part of a model I built. I had other geoprocessing tasks on the same input FC, so I just wanted to use the same input FC for the dissolve operation. Anyway, I did some work around to used my original input FC as temp Fc and used the dissolve output as my new inputFc for the other operation, and it seems working. I will try the suggested methods to see how they work. Thanks again !!Dan