Abstract: The laser pulse transmitted from satellite laser altimeter system would be refracted by atmosphere and the range error in the system was about a few meters. In this paper the atmospheric refraction delay based on refraction models and mapping function was calculated, and the method of air pressure correction were discussed. Combined with the elevation data of geoscience laser altimeter system (GLAS) and meteorological parameters of national center for environment prediction (NCEP), the atmospheric delay was calculated and compared to the GLAS results. The comparison shows the deviation of hydrostatic and wet atmospheric delay are less than 2 cm and 1 mm respectively.