The generalized shear test was performed using the dynamic shear rheometer under the stress sweep mode. When using the BoxLucas model to fit the test data, the evaluation parameter of asphalt high temperature performance including shear stress constant τ0, failure strain γ0 and generalized shear modulus Gd were developed. During data fitting, it is necessary that the strain corresponding to the end value of the stress loading is greater than 12%. If the strain corresponding to the end value of the stress loading is less than 12%, it may cause a large error on Gd. By comparing the performance of 5 kinds of asphalt, it is found that shear stress constant τ0 and failure strain γ0 are not accurate enough, it is recommended to use generalized shear modulus Gd to evaluate the high temperature performance of asphalt.