Abstract: Based on conventional observation data from 1965 to 2019 and encrypted data from regional stations from 2008 to 2019,the spatial and temporal distribution characteristics of heavy rain in Tianshui were analyzed.Meanwhile,30 representative samples of heavy rain were selected for synoptic classification and the analysis of high-and-low altitude physical quantity characteristics.Relevant forecast indicators were determined.The results revealed that:（1） In the past 55 years,the annual average occurrence of heavy rain in Tianshui was 2.75 times,showing an overall rising trend and an increase of 0.2 times per decade,while it showed a declining trend in the late 1960s and1980s-1990s,and showed an increasing trend in the 1970s and the 21st century.（2） Heavy rain occurred in Tianshui from mid-April to late-October,but occurred intensively in summer from July to August,most frequently in July.The monthly distribution showed a single-peaked characteristic,and the ten-day distribution showed three-peaked characteristic,which was closely related to the position of subtropical high.（3） The spatial distribution of rainstorm increased from west to east in Tianshui area,and there were many distribution centers.（4） There were two types of circulation patterns of heavy rain in Tianshui,namely,eastward shifting low trough（vortex） and southwest airflow on the northwest side of the subtropical high.There existed differences in their respective high-and-low-altitude physical quantity.