This paper describes the analysis of applicability of Downdraught Cooling in three climates of China based on development of climatic applicability maps. Maps ware base on a new approach of three related climatic characteristics of each locations: CDH (Cooling Degree Hours), DBT-WBT (Dry Bulb Temperature-Wet Bulb Temperature) and 26℃-WBT (26℃-Wet Bulb Temperature). The potential opportunity of using different type of downdraught cooling, such as PDEC (Passive Evaporative Downdraught Cooling), ADC (Active Downdraught Cooling) and PHDC (Passive Hybrid Downdraught Cooling), as an alternative or a complement to conventional air conditioning systems was accessed for different climate regions. Three cities representing the three major climatic regions (hot and dry, hot and moderate humid, hot and high humid) were selected for climatic analysis. The bioclimatic charts are used to test whether passive downdraught evaporative cooling, in conjunction with natural ventilation, night ventilation, high thermal mass with night ventilation, solar shading, might achieve summer thermal comfort in different climates of China. Summer time hourly climatic points were plotted on the psychrometric chart for each city.