Abstract: Based on data from 61 national observation stations from 1960 to 2013 and NCEP (National Centers for Environmental Prediction) reanalysis data,the environmental and physical quantity fields of a rainstorm at multiple time periods in Liaoning province were synthetically analyzed using synoptic meteorology and physical diagnosis methods.Sixty regional heavy rainstorm processes were selected in this study.The results show that the heavy rainstorms in Liaoning province are controlled by the interacting results among polar,westerlies,subtropic and tropic systems.The cold polar air that is entrained by cold shear lines at low layer invades Liaoning province from a more northerly path.A low-level jet is strengthened by the eastward movement of the westerly shortwave trough.It makes the ground convergence line form a front and at last triggers a heavy regional rainstorm.The falling area and strength of heavy rainstorm in Liaoning province are related to the paths and strengths of the low-level jet and cold and warm air.The moisture and thermal conditions are the bases for the generation of a heavy rainstorm.The dynamic uplifting condition is a determining factor for the intensity of precipitation.It proves that the composite analysis of environmental and physical quantity fields can reveal the common issue in the heavy rainstorm in Liaoning province.It expects that this work could provide a useful reference for forecasting heavy rainstorm in Liaoning province in the future.