Using Gaussian decomposion method, we analyze the characteristics of Z-scan curves for nonlocal nonlinear materials in this paper.We provide the normalized transmittance expression for determinating the nonlinear refractive index of nonlocal nonlinear medium based on Gaussian nonlinear response, analyze the influence of the degree of nonlocality on the Z-scan curves, show the methods of measuring the nonlinear refractive index of nonlocal nonlinear medium and the degree of nonlocality, discuss the adjustment brought about by the degree of nonlocality and suggest some feasible measurements. In addition, the numerical results on the base of sech response are obtained and compared with the results on the assumption that the nonlinear response of the nonlocal media is Gaussian.