Abstract: Geological background of Sichuan-Yunnan region is complicated. Many methods based on active or passive sources have been used to study the crustal and mantle structure of the region. We apply Virtual Deep Seismic Sounding(VDSS) technique, after correcting arrival time anomaly of direct Ss wave, to get crustal depth distribution of this region. In region with less variation in crust, our results agree well with those of former researches. We provide new constrains on Sichuan-Yunnan’s crustal and mantle structure research.