Computational accuracy and speed are two factors that divide the radiative transfer models into two categories “accurate models with high spectral resolution” and “fast models”. The goal of this study is to assess the output of the rapid radiative transfer model for General Circulation Models, RRTMG, using a high-resolution radiative model called line-by-line radiative model, LBLRTM. To this aim, the both models with the same initial conditions are implemented in the selected wavelength intervals, 10-350 cm-1 and 820-2600 cm-1 and the values of radiative heating rate are calculated for each model. Results show that RRTMG has a high accuracy in 10-350 cm-1 wavelength range, especially in the lower troposphere, due to dominant radiative effects of H2O in the both models. In the 820-2600 cm-1 range, regardless of the radiative impacts of some atmospheric gases in RRTMG, a slight difference is observed in the lower troposphere, which decreases with increase of altitude.