Abstract: When the strength reduction method is used to solve the problem of slope stability, the failure criteria have direct relationship with the safety factor. The smoothed particle hydrodynamics (SPH) method is a new mesh-less method, which is developed recently due to its advantages in the field of large deformation, is also applied to slope stability analysis. However, no discussions about the failure criteria of slope stability analysis based on SPH are available until now. Firstly, the slope stability analysis procedure based on SPH is written in Fortran language. Then, the influences of different failure criteria on the safety factor are discussed through a typical slope case, and a new displacement change failure criterion is proposed. The case shows that in the slope stability analysis based on SPH method, the plastic zone criterion and the displacement change criterion have their own advantages and disadvantages, but the safety factor obtained by the two criteria are quite close to the safety factor obtained by the limit equilibrium method or finite-element method, and both of the two methods can be failure criteria. When using the displacement change criterion, the two-step method can be used to reduce the computation time and to obtain more accurate safety factor, and it is worth recommending.