In this paper a Modified Artificial Immune System (MAIS) is presented as a powerful tool for data classification. We discuss how Artificial Immune System (AIS) could classify data inspired by the natural immune systems. Inspired by the interaction between electric charges, some modifications are performed to calculate the Stimulation Level (SL) of the B cells. Furthermore, a novel method for cloning and updating of immune cells is proposed. Finally, some simulation results are presented with sample and realistic data. The results are compared with the conventional AIS and some other classification methods