Abstract: The paper aims to explore the influencing factors on typhoon’s track and precipitation. Based on the NECP/NCAR and NOAA data and the precipitation data, and by using fortran software and Grads software, the causes of typhoon Fitow’s movement and precipitation were analyzed from the perspective of large scale circulation and water vapor transportation. Results showed that Fitow was continuously affected by subtropical high and westerly belt from its generating to landing. During this period, typhoon Danas pushed the subtropical high westwards and accelerated the Fitow’s landing. In the process of moving, Fitow was accelerated from October 1^st 02:00 to 2^nd 08:00 because of the strong steering flow and the moving speed decreased from 2^nd 14:00 to 4^th 14:00 due to the weakened steering flow. However, at 4^th 20:00 it began to turn to west and accelerated when subtropical high moved westward due to the enhanced steering flow. The big proportion of precipitation caused by Fitow (October 6^th -9^th) happened in Yuyao in northern Zhejiang and the southeast of Zhejiang. The whole vapor belt from southern of the subtropical high in the Pacific Ocean to Jiangsu and Zhejiang provided a continuous supply of water to Fitow and caused a heavy rainfall in Zhejiang P rovince.