Abstract:The linear deformation measurement is a useful way in rockmass monitoring , which can obtain the detormations of many places along the measuring line by setting a measuring mark every meter. To use the survey data well , and let it play more important role in engineering , the Grey Model is used to analyze the data. Combin2 ing with the features of linear deformation measurement , the model is used to describe the deformation dist ribu2 tion , monitor it s behavior in important part s , and predict the maximum deformation. With linear deformation sur2 vey data on the north slope of the permanent ship lock of the Three Gorges Project , these methods are proved to be rational and feasible.