A steady model was used to investigate the effect of building parameters on solar energy collecting efficiency of solar greenhouses in north China from 35°N to 45°N, including Lanzhou, Xining, Jinan,Yinchuan, Beijing, Huhhot, Shenyang and Urumchi. Building parameters include span, height and angles of roof. Useful solar energy and heat load were simulated from November to March. The simulation results show that when inner temperature is set at 15°C, the ratio of useful solar energy to total heating requirement (heating guarantee ratio) is from25% to 49% for the same type of production structures at different latitudes in January, while in March, the heating guarantee ratio reaches 100% in Lanzhou, Jinan, Yinchuan and Beijing, and about 65% in Shenyang and Urumchi, and that solar energy collected inside greenhouses increases with the increase of span, height and angles of roof, however, the heating guarantee ratio has little change, which means that the variation of geometrical dimensions has little effect on energy saving when compared with production structures existed. The study also suggests that the solar energy heating guarantee ratio can reach up to 40% and 60%, respectively, at latitude of 44°N and 40°N during the coldest days by increasing heat resistance of south roof and reducing air infiltration. Air temperatures inside and outside a large-scale solar greenhouse without auxiliary heat resources in shenyang were measured from December to March to validate the model.