The atmospheric circulation pattern, atmospheric stability and radar data of a severe continuous rainfall event on 6 and 7 June 2006 in Nanping, Fujian Province are analyzed. The results show that the greater the meridionality of the weather system was, the stronger the weather system was; the greater the instability of the atmosphere, the stronger of the precipitation. Under the control of a certain weather system, the merging of radar echoes from different directions foreshowed strong rains. The differences in the intrusion of cold air and the outburst of warm advection on two days were related with different precipitation intensities. The precipitation amount was well corresponding to K and SI indexes in the two cases. The greater the indexes, the stronger the precipitation. The accuracy of the refined weather forecasting can be improved by use of radiosonde data from single station and radar data.