Abstract: The distance between Triassic age Coal Bed 3 and Jurassic age red bed is about 60~220 m in Dongtan Mine,Yanzhou mining area.Generally in mining process no water inrush or less water from roof red bed,but in Nos 4308 and 14301 mining faces occur water inrush and the water yield is relatively large.The analysis results indicated that the mining operation caused the fault to activate and the height of caving zone to increase,connecting the red bed aquifer.At last,schemes are suggested to control water inrush from red bed.