Abstract: Some characteristics of kast development amd the corresponding dynamic properties of groundwater in a wide valley are studied.It is pointed out that the karst on the surface was quite developed and the relative unobstruted depth of karst developing was small because of the special topographic condition.It is also pointed oot that the karstic piping systems which usually contain the unconfined flow exist in the area close to the river,and along the system have big transmission capacity,small gradient,etc.Therefore,they would be the important domains in which the anti-leakage steps need to be taken.Finally,the formation of the double or more than double goundwater levels,which may occur in the process of drilling,is analyzed and its significance is discussed briefly.