Voice spam is a major serious issue that would lead the people's lives a few inconveniences in recent years. In this paper, a model based on user behavior pattern is proposed to design an anti spam calls technique. The basic idea for the technique is that spammers with revenue motivation behave significantly distinct to legitimate callers. The characteristic parameters representing user behavior pattern can be joined to help filter spam calls among phone system. The proposed scheme is applicable for detecting spam calls under different backgrounds and it is more simple and effective compared to existing spam calls defending techniques.