利用关岛联合台风警报中心提供的北印度洋热带风暴资料、NCEP/NCAR再分析资料和云南125个气象站的逐日降水资料，选取两次秋季强孟加拉湾风暴个例，对其移动路径和影响云南降水进行了对比分析。结果表明，两次孟加拉湾风暴的强度相近，移动路径和登陆位置不同，受其影响云南降水在强度和范围上存在明显差异。200 hPa南压高压位置、引导气流的差异导致了孟加拉湾风暴移动路径和登陆位置不同；孟加拉湾风暴环流与冷空气相互作用是产生云南强降水的重要机制；低层孟加拉湾风暴东侧西南大风区的移动对降水的形成也具有重要作用，一方面将风暴中大量的水汽和能量输送到云南，另一方面大风区的风速辐合有助于维持必要的动力学条件。受500 hPa西太平洋副热带高压西伸脊点和低层西南风强度的影响，水汽输送、辐合强度和维持时间存在差异，高低空不同的环流形势配置导致了风暴影响云南降水的动力结构、垂直运动等方面存在明显差异，而这些差异是两次孟加拉湾风暴造成云南不同降水分布特征的重要原因。

Based on the data of tropical storm over northern Indian Ocean from the Guam Joint Typhoon Warning Center, NCEP/NCAR reanalysis data, daily precipitation data at 125 stations in Yunnan, two cases of strong Bengal Bay storm in autumn were selected, then their moving tracks and influence on precipitation over Yunnan were comparatively analyzed. It was showed these two cases with nearly the same intensities, moving track and landing position were difference. During their influence period, the intensity and range of precipitation over Yunnan were obviously different. The difference of south Asian high position on 200 hPa and steering flow resulted in various of moving track and landing position of Bengal Bay storm; the interaction of Bengal Bay storm with cold air was a critical mechanism to heavy rainfall generating in Yunnan; the moving of southwester areas at lower layer on the east side of Bengal Bay storm also played an important role in the formation of precipitation, on the one hand, it transported a large number of water vapor and energy into Yunnan, on the other hand, wind velocity convergence on gale areas was helpful to maintain necessarily dynamics condition. With the influence of the western ridge point of the western Pacific subtropical high on 500 hPa and intensity of southwesterly at lower layer, water vapor transport, intensity of convergence and maintenance time were various, different pattern in circulation at upper and lower layer caused the significant differences in dynamic structure, vertical motion and so on, while these were important reasons of various precipitation distribution generating in Yunnan with two storms.