A simulation method for design of solar air conditioning system that is composed of solar collectors and an absorption chiller was developed. For the optimized design of the system, it is necessary to make an integrated simulation of the collector and the chiller based on the customer's air conditioning demand and the weather data, but for the simulation of the chiller, the refrigerant cycle simulation has to include the design data of the chiller such as the heat transmission coefficient, the heat-transfer area and the solution flow rate that designers cannot obtain easily. The developed method is based of the specification data of collector and chiller that can be obtained from their technical manuals and designers can make the optimized design for each customer.