A heavy rainstorm happened in Qingdao from September 18 to 20, 2007, w hich exceeded the historical record. The realtime data, circulation characteri s tic and Doppler radar data were used to analyze the heavy rainstorm process. The results show that there was a strong vapor convergence at low level．At the beg inning the precipitation was caused by the strong pumping at high level and was rather weak. Typhoon Wipha strengthened the convergence lifting. The activity of cold air at high level strengthened the instability. The coupling among the wes tern trough, subtropical high and typhoon Wipha formed this torrential rainstorm . Doppler radar data shows that the disturbance is active at lowlevel air. A l i near convergence band with cyclonic curve is found near sea surface. It is a sea land front caused by sealand breeze, and is also a strong rain belt companyi ng with heavy rain and strong horizontal wind shear.