Abstract: Based on the observed and investigated annual maximum point rainstorms data and meteorological data in the Liaohe River region, the regional characteristics and weather causes of annual extreme point rainstorms are analyzed, and the fundamental rules of the extreme rainstorms occurrence are revealed. The analysis results show that the amount of the annual maximum 24 h point rainstorms accounts for more than 70% of 3 d point rainstorm quantity in most areas of the Liaohe River region. Futhermore, 92.1% of the rainstorms occurs in July and Autumn, and 68.1% of the extreme rainstorms appears between late July and early Autumn. The spatial distribution of the extreme rainstorms is concentrated on the windward slope of Qianshan and Heishan Mountains and the hilly area of the Yalujiang River basin, as well as the Liao-Hun-Tai River region. The interannual variations of the extreme rainstorms are evident. The extreme rainstorms in the middle and high latitude of East Asia are characterized by “East high, West low”, “two high one low”, “wavy airflow”, and “warp direction high dam”, and in the middle and low latitude of East Asia by subtropical anticyclone stability, and in the highest latitude by upper air circulation situation as the background. The main rainstorm weather system has cyclones from the north, upper trough, single cold front, shear line, occluded front, upper vortex, cold vortex from northeast, semi tropical and semi temperate cyclone. The rainstorms usually happen under the combined action of the weather systems, such as middle-latitude westerly trough, subtropical high and tropical cyclones, and topographical uplift of the windward mountain.