中文摘要：

利用研究区（23．9°～25．1°N，97．8°～99．0°E）内瑞丽一龙陵断裂两侧4个流动数字地震台记录到的宽频带远震P波波形数据进行接收函数反演，得到了台站下方0～100km深度范围内地壳、上地幔的S波速度细结构。结果如下：（1）在研究区内，以瑞丽一龙陵断裂为界，其西北侧Moho面深度为38～40km，东南侧Mo-ho面深度约为38km。（2）断裂两侧地壳、上地幔S波速度结构存在显著差异，西北侧台站下方地壳和上地幔均存在大范围低速区；东南侧台站下方上地幔中无明显低速层，地壳内存在低速层，但范围和速度差都较小。（3）断裂两侧台站下方地壳和上地幔S波速度结构的较大差异，证明它们分属不同的构造单元。（4）研究区内的S波速度结构存在明显的横向非均匀性。

英文摘要：

The studied area is 23.9° -25. 1°N, 97.8° -99°E. The studied four digital seismic stations distributed in the both sides of the Ruili-Longling fault in the studied area. The S-wave velocity structures within the depth of 0-100 km beneath four stations are inversed from the broadband teleseismic P waveforms by receiver function. The results show ： （ 1 ） In the northwest side of the Ruili-Longling fault, the depth of Moho is 3840 km, and in the southeast side, the depth of Moho is about 38 km. （2） The S-wave velocity structures of the crust and upper mantle differ obviously in the both sides of the fault. In the northwest side, there are lower velocity zones in both crust and upper mantle beneath the stations; but in the southeast side, there are lower velocity zones only in the crust beneath the stations, and their range and velocity difference are small. （3） It is proved by the obvious difference of S-wave velocity structures between the both sides that the both sides of the Ruili-Longling fault belong to different structural units. （4） In the study area, the S wave velocity structure shows strong horizontal heterogeneity.