The propagation of nonlinear surface waves along the boundary of LiNbO3 crystals with diffusion and photovoltaic nonlinearities is investigated theoretically and experimentally. Surface waves with different oscillating period are obtained by changing the values of the propagation constant, and the energy of surface waves would increase monotonically with the propagation constant. Our experimental results are in good agreement with the theoretical analysis. Experimental results show also that the generation of surface waves can be shortened by increasing the power of the input beam; and the excitation efficiency of the surface waves can be enhanced by increasing the angle (less than 90 degree) between the input beam and the crystal c-axis.