Abstract: Since more than 90% of the mesocyclones are accompanied by severe weather such as tornadoes, severe hails, strong winds etc., it is a great signifi cance to identify the mesocyclones and apply to publishing the severe weather warning in real-time for more accurate. At present, only the CINRAD WSR-98D SA/SB in China has mesocyclone algorithm, which was developed by US National Severe Storms Laboratory, and mesocyclone products. While other types of Doppler radar have to recognize mesocyclone by using radial velocity maps artifi cially only. This paper reviews the evolution of the mesocyclone criterion for three stages in the operational application, and analyzes some issues in the third stage. Based on the development of the mesocyclone algorithm, this paper introduces the mesocyclone shear algorithm, mesocyclone algorithm and mesocyclone detection algorithm,and discusses the operational applications and the issues of products from the mesocyclone algorithm.