By collecting and reprocessing current reflection seismic profiles, the authors get a 270 km profile across the Qiangtang basin at S-N direction. Profile shows: there are probably Proterozoic basement in Qiangtang basin. The depth of the basement is changeable; it is deeper in South Qiangtang basin and shallower in North Qiangtang basin. Shallow crustal deformations (about 0~3 s) are quite different between North Qiangtang and South Qiangtang. In North Qiangtang, there are strong fold deformations and alternating uplifts and depressions, and relatively flat in South Qiangtang. Continuous arc reflections were found beneath the central uplift of the Qiangtang terrane.