The typhoon No. 0716 (Krosa) landed on the vicinity region between Zhejiang Province and Fujian Province at 1530 BT 7 October 2007 for the third time. An outer spiral rainband passed through the dualDoppler radar observation domain that was composed of Ningbo and Zhoushan Doppler radars. Three dimensional wind field was retrieved by the dualDoppler radar data. The mesoscale structure of the spiral rainband was investigated by the 3D wind. It shows that there were some strong reflectivity areas in the low level of the rainband region. The inflow in the upstream of the rainband outside was weak. On the other hand, the inflow in the downstream of the rainband outside was strong. There was outflow in the inside of the rainband at the low level. In the vertical crosssection, there was inflow in the low level of the outside rainband. The inflow entered the rainband at low level (z<2 km) from the outside rainband. On the contrary, there was outflow in the inner side of the rainband. These flows converged at the low level of the rainband central region. The tangential component of the wind decreased with height and the maximum wind region was at 2 km level.