Abstract: The height of development and its morphology of distrbution for the water flowing fractured zone was the basis of reasonable confirmation of the mining boundary and remaining water barrier.In order to discuss the effect of overburdens under injecting grouts in separate layers on the morphology of the water flowing fractured zone,continuous exploration for failure characteristics of the overburden of working face 14308 of Dongtan Coal Mine under injecting grouts in separate layers and fully mechanized sub-level caving condition was processed by the method of underground uphole water injection technology by intervals with bore-head leaking multi-loops affusion(discharge) system.It was shown that the height of the water flowing fractured zone under injecting grouts in separate layers condition was slightly higher than that under normal condition,and the height was lower along the strike of the coal seam than that along the tendency of the coal seam.Its range had the larger outstand to outboard working face under the condition of injecting grouts in separate layers.