Abstract:The real time typhoon subjective positioning data from National Meteorological Centre, precipitation observation data from 124 national weather stations in Yunnan Province and the NCEP reanalysis data with 1.0°×1.0° horizontal resolution and 6 h temporal resolution are used to analyze the influence of No.1213 TC “Kai tak” and No. 1309 TC “Jebi” on Yunnan. The characteristics of the tropical cyclone (TC) moving path, circulation field, cloud, water vapor, dynamic conditions are analyzed. The results show that while “Kai tak” influences Yunnan, the position of Qinghai Tibet high pressure is by west and the subtropical high is zonal. TC lies in the southeast to easterly wind of the southwest side of the subtropical high, so the path of TC is the west path. But when “Jebi” affects Yunnan, the position of Qinghai Tibet high pressure is by east and the subtropical high is massive. TC is in the southerly wind of the west side of the subtropical high, so the path of TC is the northwest path, and the central part of Yunnan is in cyclonic wind field where the southwestern airflow and the subtropical high periphery south airflow gather creating heavy rainfalls there. When the two TCs affect Yunnan, the lower troposphere has a larger transport of water vapor. The water vapor mainly comes from TC, the South Sea of China and the Bay of Bengal. Moisture convergence center is in the front of the low pressure inverted trough, impacting the central and southern part of Yunnan from east to west along with the weather system. Heavy precipitation zone has convergence in lower level and divergence in higher level. Strong upward motion provides favorable dynamic mechanism for precipitation and releases unstable energy. Therefore, the forecasting of the shapes and positions of the Tibetan high and subtropical high is beneficial to forecasting the moving path of tropical low after its landing so that the forecast of rainfall intensity and location can be more accurate.