The authors analyze the causes of abnormal rainfall in Shenzhen in June 2008 based on the NCC/CMA data. The results indicate that the abnormally low sea surface temperature in the equatorial western Pacific during July 2007-Februry 2008 and the more spacious snowy area over the Qinghai-Tibet Plateau in the winter before June 2008 were the climatic background of the abnormal rainfall in Shenzhen. Moreover, the blocking high was much stronger in Northeast China and the Urals long-wave trough was abnormally deepening in June 2008, which promoted the meridional circulation. At the same time, much stronger cold air mass outburst in China frequently in the form of ladder troughs, which provided energy for the Shenzhen rainfall. Finally, the subtropical high was stronger and shifted southward, stronger monsoon transmitted huge water vapor and heat, and cold and warm air masses converged in Shenzhen frequently; these were the causes of the abnormal rainfall in Shenzhen. In summary, all the above conditions worked together and resulted in the abnormal rainfall in Shenzhen.