By using the hourly precipitation data of 111 national stations in summer (June to August)during 1991-2015 in Inner Mongolia, the short-duration intense precipitation (1 hour precipitation over 20 mm)was verified in different zones (extreme arid regions, arid regions, sub-arid regions, sub-humid regions, humid regions) of Inner Mongolia. Short-Duration Intense Precipitation (SDIP) was defined by cumulative probability method in summer in different zones of Inner Mongolia. Results reveal that:annual average precipitation and Extreme Value of Hourly Precipitation (EVHP) increased from extreme arid regions of west to sub-humid and humid regions of east in Inner Mongolia. High value area was located in the east of Greater Khingan Range mountain rage and the secondary high value area was in the south of Yinshan mountain. EVHP was less than 20 mm in extreme arid regions in Inner Mongolia, but EVHP was greater than 50 mm in sub-humid and humid regions of Inner Mongolia, so far as to exceed 100 mm. Annual average frequency of Hourly Precipitation (HP)greater than 20 mm was only one times in the east of sub-humid and humid regions, the rest areas were less than one times. It belonged to extreme rainfall that HP reached 6.1 mm·h^-1,9.8 mm·h^-1,12.5 mm·h^-1,15.2 mm·h^-1 and 14.3 mm·h^-1 respectively corresponding to extreme arid regions, arid regions, sub-arid regions, sub-humid regions and humid regions of Inner Mongolia. HP greater than 20 mm was unsuitably definition of SDIP in Inner Mongolia. Based on the above research, to combine terrain and landforms of Inner Mongolia, SDIP in extreme arid regions and arid regions defined 5 mm, SDIP defined 10 mm in other zones.