This research work is devoted to the improvement the Hybrid Integral Aproach (HIA) proposed by Nguessong et al. for the characterization of the nonlinear elastic response of rubber-like materials. The improvement is based on the choice of the approximation of the inverse Langevin function for the molecular part and on the modification of the second term I-2 for the phenomenological part. Thus, in the new proposed model, we retain the approximation of the inverse Langevin function defined by Marchi and Arruda to improve the first term which represents the molecular part. With this approximation, the relative error is very minimal (0.0015%) compared to the others approximation existing. The second term of this proposed model comes from the Gornet et al. model. This model contents six rheological parameters optimized by the Levenberg-Marquardt method. Two sets of experimental data (Treloar data and Nunes and Moreira data), from the literature, are used to compare this proposed model with initial HIA model. With Treloar rubber, data the simple tension suffice to determine the parameter values. Thus, the fit of the experimental data has been shown to provide an accurate response and predictive description in biaxial tension and pure shear with the same sets of material parameters. Unlike with Moreira data, this proposed model gives directly the material parameters in simple shear with good correlation. On the other hand, comparison is made between the proposed model and the HIA model. The proposed model is most efficient, because the proposed model emerges from a very small relative errors with Treloar's experimental data: 0.01 0. 0.04 in simple tension, 0.02 +/- 0.006 in biaxial tension and 0.07 +/- 0.005 in pure shear.