Abstract: In this paper we focus on the anti-collision algorithms in RFID systems and discuss two methods for fast tag identification: Memory less Query Tree (MQT) and Intelligent Query Tree (IQT). These methods can be used for enhancing the identification speed of RFID systems. Compared with the normal query tree protocol, MQT and IQT protocols have lower communication overhead. MQT and IQT protocols have better performance with adopted two phases: first reading cycle and second reading cycle and they have minimal change in tag hardware complexity. In this work we describe two protocols and compare them with QT protocol in the number of query transmissions and number of bit transmissions. Mathematical results show that protocols with two phases can avoid of collisions better than QT protocol in RFID systems.