Abstract: Based on observation data of Rizhao city，Shandong province from 2007 to 2016，interannual and interdisciplinary characteristics of 49 severe precipitation process in Rizhao were analyzed.According to influence system of heavy rainfall，weather conditions of heavy precipitation in Rizhao were classified and analyzed，key environmental parameters of heavy rainfall in different seasons were also analyzed.Results showed that number of heavy precipitation in July-August was the largest and influence was also the largest.Weather conditions of heavy rainfall in Rizhao could be divided into low-slot cold front type，low vortex shear type，cyclone type and typhoon type，low-slot cold front type was main weather type of heavy precipitation in Rizhao.Upstream and Qingdao（T-Td）850，Qingdao（T-Td）700+（T-Td）850，850 hPa water vapor flux divergence，850 hPa pseudo-equivalent bit temperature，K index ，the maximum rising rate of 850 hPa had good indication of heavy rainfall in Rizhao.