Abstract: The process of a local heavy rainfall event with heavy-hard rain from August 6 to August 7 2016 in Chaoyang City of Liaoning Province was analyzed using the precipitation information provided by Micaps system and the radar product information provided by PUP.The results showed that this event was a typical rainfall process： two-ridge and one-trough was its circulation background;a cold front shear steadily maintained at 700 hpa;a low pressure system was in northern area of ground;triggering condition for uplifting existed.Meanwhile,the vapor energy was continuously supplemented by southwest warm-wet air and the positive wind-stress curl continuously inwardly transmitted and conducted,resulting in the enhancement of low-pressure system development in low altitude.