We study the basic characteristics of load displacement curve(P-S curve) of uplift anchor in this paper.According to the property of rock mass,we analyze the development trend of two kinds of curves.Based on the basic characteristics of P-S curve of uplift anchor,we verify theoretically the feasibility of hyperbola model,exponent model and power function model,compare the advantages and disadvantages of the three models at Pu/2 position(the half of ultimate bearing capacity),and use the three models to fit the measured data to further verify the accuracy and applicability of each model.The results show that the power function model has the highest precision and wide range of application,while exponent model is moderate in accuracy,and hyperbola model is relatively worse than the aforementioned ones.The steepness of the P-S curve of the uplift anchor is related to the upper convex exponent of the power function,and the curve is steeper when the upper convex index is between 0.75-1.It is suggested that the proper mathematical model shall be selected to describe the curve type according to the actual rock mass properties,and the power function model is preferred when describing the P-S curve of anchor bolt.