Abstract: Cold vortex (or cold low, also called cut-off low), characterized by a cold core and low pressure center over 500 hPa level, is one of the most frequent weather systems over Northeast China. It is often accompanied by strong convective incident, and can bring a wide range of continuous rainfall. However, most of the past researches mainly focus on the environmental conditions and large scale of the cold vortex systems. There is little analysis on meso-scale structure of the convective systems of cold vortex, especially using satellite and radar data, and the understanding on the vertical structure of the meso-scale convective systems is limited. CloudSat data, NCEP reanalysis data and visible light satellite data has been used to analyze the convective rain bands and meso-scale cloud structure of different stages of a cold vortex over Northeast China during 20—24 July 2006.The results show that at the beginning of development stage, the structure of the warm front is characterized with isolated and deep convective systems. At the development and matured stage, the intensity of radar echo is weaker than its development stage, and the convective systems are shallow. The echo top of occlusion under the cold vortex system presents some special characteristics: In the southeast of occlusion, the echo area is driven by the cold-dry air; in the middle area of occlusion is the main convective system and in the northwest area echo is caused by the lifting effect of warm front confront the cold front. There is delamination between ice water and liquid water at the tail of the occlusion front. The height of incursion layer of dry-cold air is about 5 km, above which is the weak echo consisting of ice water, and below the incursion layer is the echo with liquid water. At the mature stage of the cold vortex, the convective systems are located mainly outside the cold vortex in the form of isolated convective systems. Convective systems which contains plenty of ice water content are mainly located in the north of the cold vortex, while liquid water content exists below the 0℃ layer of the cold vortex center.