Abstract: The study aims to identify the characteristics of the path of typhoon northward, the method to locate typhoon center and the major factors of storms caused by typhoon. Based on historical database retrieval system as well as high level and surface data, the author analyzed features of the location, track and intensity changes of typhoon Damrey after it entered into Bohai sea and its synoptic and dynamic mechanism. Results showed that: (1) typhoon center location could be subjectively determined by surface wind convergence along with depression when typhoon cloud was not significant; (2) Track of typhoon Damrey was influenced, on one hand by interaction and combination with westerly trough in mid and high latitudes, and on the other hand by jet stream over the southwest side of subtropical high (SH), which was enhanced by the binary typhoons on the south side of SH, and the path of typhoon Damrey was mainly affected by the edge flow of SH; (3) Damrey was mainly weakened by low SST and invasion of lower level cold air.