Abstarct: This work presents feasibility studies for the usage of a ammonia- water solar absorption system for refrigeration purposes in cold stores. In this regard, a comprehensive computer model with using the MATLAB, EES softwares and 20-year weather data was developed with the general purpose of modeling, simulation, optimization and hourly performance prediction of the solar absorption system. As a case study, a cold store with a capacity of 5,000 tons of apples in Tehran, Iran was studied with the assumption that the product was introduced from September 22 st for 40 days and stored until March 31st. And the hourly performance of the system was analyzed and the optimal values of the thermal tank volume, area and mass flow rate of the collector, the auxiliary set-point temperature and the optimum tank temperature at the time of system start-up were determined at all critical days of the period. In order to improve the system's performance, three idea proposed; using a refrigerant storage tank, monthly setting of the absorption systems low pressure, and monthly control of the heat exchangers cycle between the collector and the thermal tank. the effect of each of thise ideas on the system's performance was investigated in detail. Cooling Loads in the months of September to March was estimated at 515.40, 554.04, 211.71, 199.49, 204.63, 212.92 and 217.68 kW, respectively. The optimum value of maximum area of the vacuum tubular collector was determined 4061, 4910, 2680, 2526, 2126, 1688 and 2415 m2 respectively in September-March, and the optimum volume of storage tank to collector area was determined in the range 9.16-18.67 lit/m2.