Based on the daily SARS(Sever Acute Respiratory Syndrome)patients and local meteorological factors in Beijing and Hongkong,we conclude that air temperature and pressure had a high correlation with the incidence of SARS;high relative humidity,cloudy weather and the lack of sunlight were the common meteorological characteristics,and the cold air activities promoted the prevalence of SARS.In this paper we also formed an integrated index based on the corresponding relation of the number of SARS patients and meteorological factor changes,then calculated the high danger index(Zj)of air temperature in Beijing and Hongkong,and results show that daily average temperature and daily minimal temperature indices have a 3℃and 7℃differences,respectively,while the maximum temperature index are both 24-27℃in the two regions.