In Taiwan, ”Fan and Pad” is the most popular evaporative cooling system used in Greenhouses. Besides the review of basic theories and factors affecting the performance of the system, the design rules, governing equations on designing a system as well as important issues on operations and maintenances were all mentioned in this paper. The suitability of fan and pad system in Taiwan was also investigated based on 11 years of hourly weather data collected by Central Weather Bureau of Taiwan.