The "338"tin mine located on Baisha Town of Changning City in Hunan Province, the kaists crevasse grit-filled tin deposit, had a serious water-penetration and putty-gushing accident in 2# admission passage of 95m center-section, causing five-person dead on May 22, 2005. By analyzing the ore deposit hydrology geological data, the mining technology and the geologic structure, this paper concludes that the blasting during mining tunneling process destroying the aquifuge of karsts pipeline is the immediate cause of this accident, and the continuous raining increasing the hydrodynamic pressure in k...