Abstract-The present paper summarized the results of the most commonly adopted calculation models for total solar irradiance on inclined surface. The solar irradiance on inclined surface in Beijing was taken as an example and was simulated using Liu and Jordan, Klucher, Hay, and Perez sky models and the results were analyzed in a variety of circumstances. The modified Klucher model was improved with the introduction of the correction for tilt angle β=0° and the suitability of all the five calculation models was analyzed.