Correct division of water bearing formation and type of groundwater is very important for estimate the groundwater resource. In this paper, the authors thought that the interstratified impure carbonate rock should belong to bedrock fracture groundwater bearing formation. Its groundwater should belong to bedrock fracture groundwater. It’s better to deduct the distribution area of mudstone, siltstone and shale when estimate the interstratified impure carbonate rock groundwater resource.