Recently paddy levee collapse has been increased due to neglectable management such as the omission of the levee coating and the occurrence of localized torrential downpours. Because of levee collapse, ponding depth can not be hold, and it needs a lot of expense to restoration and effort. For the development of levee reinforcement technology, the reasons of levee collapses, collapse scales, damaged forms at 3 districts(Yangpyeong, Hwasung, Cheongwon), where the levee collapse often occurs, were investigated as the basic data. From results, the main factors of the levee collapse were levee gradient and the portion of clay ratio. Too low or too high clay contents in soil was one of collapse reason.