n this paper, the weather climate features and the laws of spatial and temporal distribution of night rain and fog rain in the Xishuangbanna area are studied. The formation mechanism of night rain and fog rain and their agroclimatic significance are analysed. The results show that the precipitation in Xishuangbanna presents a proportional state between the night rainfall and the daytime rainfall, in which the rate of night rain reaches 54.5%～57.7%. Especially during the foggy season and the hot dry season the night rain may reach 71.4% and 70.6% respectively. The formation of the night rain is mostly due to the orographic rain caused by mountainous wind circulation. Its rainfall intensity is weak and its rainfall hours is long. So it is highly efficient for the tropical crops. The night fog rain plays a very important role in the eco environment of crops, for it can partly relax the insufficiency of crops water requirement during the drought season. For this reason, the night rain and fog rain resources will become the important basis in making the drought prevention countermeasures in Xishuangbanna.