Abstract：In order to study the characteristics of downburst under weak vertical wind shear, based on SA Doppler weather radar, sounding and surface (10 m) maximum wind data and cloud image data of stationary meteorological satellites, 381 downburst events under weak vertical wind shear in Jiangsu from June to September in 2019 and 2020 were selected and divided into three categories according to the scale: microbursts, macrobursts, and downburst clusters. The statistical results show as follows: 64.9% of thunderstorm days in Jiangsu from June to September were accompanied by downburst, with an average of 8 downburst events per downburst day. The proportions of three types of downbursts are 21.7% for microbursts, 47.6% for macrobursts, and 30.7% for downburst clusters, which are concentrated at 15:00 to 16:00 (Beijing time). Based on radar radial velocity, the average duration of downbursts is 25.4 min, and the average intensity (radial velocity difference of divergence couplets or extreme radial velocity at low elevation) is 22 m·s-1. Only 7 times of downbursts reached the standard of disaster wind (extreme radial velocity at low elevation reached 25 m·s-1 or radial velocity difference of divergence couplets attained 40 m·s-1). The average surface maximum wind caused by downbursts observed by ground meteorological stations is 15.5 m·s-1, indicating that downbursts’ disaster-causing potential is not significant. The low elevation radial velocity modes of downbursts are dominated by divergence velocity couplets (73.3%), but the majority are asymmetric while only 6.1% of downbursts are symmetrical divergence velocity couplets. 26.7% of downbursts exhibit strong winds at low elevation.