Based on the precipitation data recorded in Site D105 during the Intensive Observation Period of GAME Tibet (May~September, 1998), the features of the summer monsoon precipitation in the northern slopes of the Tanggula Range, Tibetan Plateau, has been analyzed The observation period was from June 7 to September 18, totally 104 days Among them, 81 days precipitation occurred The total precipitation was 279 2 mm in the period, equivalent to a daily mean precipitation of 3 45 mm It is believed that about June 7 was the onset day of summer monsoon in northern slopes of the Tanggula Range, 1998 The maximum monthly precipitation, 121 6 mm and accounting for 43 6% of the total precipitation, occurred in August In the summer monsoon period, the active phases and break phases of the monsoon precipitation existed significantly The main period was about 5 days The local convection cloud precipitation played an important role not only to the precipitation amount but also to the precipitation frequency at the Site D105