In this paper we propose an approach for intrusion detection system for database management system .Our approach concentrate on security policies for transactions permitted with DBMS. Our approach is designed to mine audit log of legitimate transaction performed with database and generate signature for legal transactions as per security policy. The transactions not compliant to signature of valid transaction are identifies as malicious transaction. As security mechanism available with DBMS is not enough to detect intrusive actions, privilege users or unauthorized users executes malicious transaction to access crucial data. So security features can be enhancing by adding intrusive detection technology to Database management system.