Velocity structure beneath active faults in the Beijing area has been discussed, based on the digital crustal model of velocity from deep seismic sounding profiles and tomography imaging of P waves. We found that there exists nearly vertical deep faults beneath the Shunyi Depression and the Machiko Depression, which are very likely to be seismogenic faults in the future. In the superficial crust, the north segment of the Shunyi-Qianmen-Liangxiang fault, the north segment of the Huangzhuang-Gaoliying fault and the Qinghe fault show a trend to converge but without intersecting with vertical deep faults. This kind of seismo-tectonic state has great potential to generate large earthquakes.