The hourly-emerged precipitation product with the horizontal resolution of 0.1° over China which is derived from the hourly precipitation observed by automatic weather stations in China and CMORPH satellite data and the average wind field and divergence field with 6-hourly temporal resolution of Reanalysis Interim reanalysis data of the European Centre for Medium-Range Weather Forecasts (ECMWF) are used in this paper to study the diurnal variation characteristics of summer precipitation in the Tibetan Plateau. The spatial distribution characteristics of the night rain in the plateau and the diurnal variation of precipitation in different durations are discussed. The results show that: (1) The diurnal variation of precipitation and precipitation frequency in the plateau are shown the peak from 18:00 to 20:00 and the valley at 12:00. (2)The spatial distribution characteristics of the daily peak and valley of summer precipitation in different regions of the plateau are different. The diurnal variation of the summer precipitation in the south of the plateau is about the same as the diurnal variation of the total precipitation in the plateau. The precipitation in the south of the plateau is shown the peak in the evening and the valley at noon. The diurnal variation in the north is different from the diurnal variation in the entire plateau. The precipitation in the north of the plateau is shown the peak in the morning and the valley at the early morning. (3)There are obvious regional differences for the night rain rate in the Tibetan Plateau. The high value center of night rain rate appears between 84 °~93 ° E and 28 °~30 ° N, with a clear distribution of "high in the middle and low in the north and south". The high value center of night rain rate is over 75%. (4)Short-term rainfalls (About 60%-80%) are more frequently than long-term rainfalls (About 20%-40%), but about 70% of the total precipitation comes from long-term rainfalls. (5)The diurnal variation of precipitation in the Tibetan Plateau is consistent with the variation of wind and divergence fields. The change of divergence may be one of the important reasons for the changes of precipitation in the Tibetan Plateau.