Improved RFID anti-collision algorithm based on ALOHA Abstract：In order to solve the problem of low efficiency of electronic tag identification in RFID system，a new ALOHA anti-collision algorithm was presented.In this algorithm，the coefficients of the tag estimation were automatically changed by using the dynamic adjustment method，which made the number of tag estimation could be dynamic changed with the number of identified tags，then the number of tags to be identified was estimated.And for the frame length adjustment，it could be determined by the relationship between the length of the frame and the tag number according to the estimated number of tags.With the tool of MATLAB，the results show that the proposed algorithm can significantly improve the throughput and stability of the system.