The design guidelines of domestic vehicles are almost originated from northern counties such as Japan, USA, Korea etc. With a hot and humid weather in Taiwan, the required cooling load of the vehicle is larger than that of original design. The power consumption of air-condition system is often over 10% of the engine output power. A larger cooling ability may consume too much power but a smaller cooling ability, on the other hand, cause a discomfort environment. Therefore, this study develop a new vehicle air-condition cooling system specifically designed for local weather condition by using the theoretical analysis. A rapidly and useful prediction method for vehicle cooling load was developed in this study. This study also can build up our own design capability, and in turn to promote the oversea market.