Abstract: Based on the detection data of weather radar (CINRAD/CC) and more surface automatic weather stations in Dali prefecture,a heavy precipitation process on August 11—12,2013 has been analyzed.The results show as follow:the precipitation process was affected by the convergence zone of Tibetan high and subtropical high on 500 hPa and the southwest airflows on 700 hPa.Viewing from the radar echo figures,the intensity of mixing precipitation echoes mainly composed by stratiform cloud echoes was less than 40 dBz,and there were wind field characteristics of warm advection and convergence in the radar radial velocity fields.Both the long duration of southwest airflow at low layers and the invasion of the cold air at the middle-upper layers of troposphere had close relationships with the occurrence and maintenance of the heavy precipitation.The divergence fields and vertical velocity fields calculated by improved EVAD method altered with different phases of the heavy precipitation,which had a great indication for forecasting the strengthening and sustainment of the precipitation.