Abstract: This paper aims to further understand the causes of thunderstorm gale in south China and provide a reference for its forecast. Based on conventional observation data, automatic weather station data, Doppler radar data and NECP 1°×1° reanalysis data, the causes of successive high wind processes in Guangxi and their differences had been studied. Results showed that: (1) the“3.30”process happened in the warm area, but “3.31”process was triggered by the surface front; (2) both of the two processes occurred in a favorable environment with an unstable stratification, vertical wind shear and strong storm potential; those conditions were stronger in the“3.31”process; (3) stratification characteristic showed significantly lower wet layer in both two processes, with clear dry layer on top of it, but the wet layer in“3.31”process was shallower and with higher specific humidity; (4) convective storms were generated and moved along the surface convergence line or strengthened when moved onto convergence line; the convergence line of“3.31”process was in a larger scale, which moved slower; (5) radar echo characteristic showed that the“3.30”process was caused by local single-cell storms or multi-cell storms, but the“3.30”process was caused by organized large-scale strong squall line (bow echo). The study indicated that there were differences in the instable stratification, the strength and construction of the mid-low level vertical wind shear and the scale and velocity of the surface convergence line between well organized storm and single-cell storm.