In this paper we present an x rescaling paramenters' formula for partons in the extended x rescaling model,where we have established the connection between the rescaling parameter and the mean binding energy.Using x rescaling parameters obtained by the x rescaling parameters' formula,we calculate the average nucleon structure function ratio of DIS process in l-A(Al,Ca,Pb)collision to l-C collision respectively.The result is in good agreement with experimental data.