A mathematical model of a solar ejector refrigeration system is developed. The system uses R141b as refrigerant and is performed using TRNSYS software and the model. The cooling load of an office building, which area is equal to 200 m², were also calculated using TRNSYS software and the meteorological data of Tai Yuan, China. Result shown that, the cooling capacity and the thermal coefficient of performance (COPh) of the system with different throat area ratio ejectors were derived. The heat collecting efficiency of the collector increases with solar radiation intensity. The temperature of the storage tank is also influenced with solar radiation intensity. Under the condition with an evaporation temperature of 8℃, a condensation temperature of 32℃ and the generation temperature is controlled to ensure that the entrainment ratio of the ejector is maximum value, the COPh of the system increases with the throat area ratio of ejector and can reach the maximum of 0.3 as r= 8.8. The independent solar ejector refrigeration system cannot meet the cooling load of users in the whole day. On the typical meteorological date August 1, the system, using the ejector with throat area ratio of 6.6, can provide 65% of the total cooling capacity which the user needed in the whole day and cannot meet the cooling load in each hour, which need variable speed compressor supplemented and the power consumption is the smallest.