The nearly 40 years data of nocturnal torrential rain was studied for 34 weather stations located in the Eerduosi Basin and its surrounding area with characteristics of arid and semi-arid zone,and desert region.The daytime and nighttime distribution of torrential rain in the basin and surroundings was analysed.The extremes of torrential rain during daytime or nighttime was given.The orographic influence on the nocturnal torrential rain was discussed.