Through the investigation of variations in oxygen and carbon isotopes sur-rounding orebodies in Shuiximiao deposit of Limu area, Wuzhishan, Jiuban de-posit of Jiahui area and Shuiyanba ore district of Pinggui area, the authors havediscovered that the isotopie determinations can be used to draw contour linesand predict as well as delineate blind orebodies.