Abstract We obtain the 10-40 s phase velocity structure of the study area based on the ambient noise tomography method and records from 70 stations in Liaoning and adjacent areas in 2012. The 3D S-wave velocity structure of 10 - 40 km below the study area is inferred by Markov Chain Monte Carlo(MCMC) method using the obtained base-order surface wave phase velocity dispersion curves. The results show that the S-wave velocity distribution in the shallow, middle and upper crust of the study area corresponds well with the topography, and the transition zone between high and low velocities is more likely to be the seismogenic zone. The S-wave velocity structure in the middle and lower crust to the top of the upper mantle is more controlled by the undulating state of the Moho surface and the deep major fractures. At 30 - 40 km depth in the area from Haicheng to Dalian and finally to Liaodong bay, there is an “arc-shaped” low velocity anomaly, and we infer that there is thermal material upwelling in this area. An elliptical low-velocity body occurs 15 km below the Liaoyang to Yitong section of longitudinal profile C-C′.