Abstract: The net primary productivity for grassland in Sichuan under different conditions and relevant solar energy utilization efficiency have been analyzed. The results indicate that when other conditions are optimal, the weight ed average of the net primary solar energy potential productivity (Yp) in the whole province, depending on the photosyn the tic active radiation (PAR), is 75. 88 t/ha/a; the net primary solar temperature potential productivity (Ypt), depending on PAR and temperature, is 44. 14t/ha/a; the net primary climtic potential productivity (Yptw) is 40. 26t/ha/a; the net primary productivity of the natural grassland (Yan) and the net primary productivity of the artificial grassland at present time (Yes) are 11. 26t/ha/a and 25. 15t/ha/a respectively. The solar energy utilization efficiencies of Rp, Rpt, Rptw, Ran and Ras corresponding to Yp, Ypt, Yptw, Yan and Yas are 4. 82%, 2. 86%, 2. 61%, 0. 71% and 1. 58% of PAR respectively.