Abstract:Based on nine climatic factors which affect the growth of Alnus formosana, the adaptive regions forintroduction of the species were investigated using the fussy resemble priority ratio method (FRPR). The nineclimatic factors are mean annual temperature, mean temperature of the coldest months, mean temperature of the hottest months, extreme minimum temperature, extreme maximum temperature, mean annual cumulativetemperature ≥10℃, mean annual precipitation, the number of months with monthly precipitation <50 mm in a year，and mean annual sunshine hours．The results show that the adaptive regions cover over 1 0 provinces along the Yangtze River and its southern areas．The most adaptive regions are in southern subtropical and tropical zones, and followed by middle subtropical zones．The conditions that suitable for the growth ofA．formos are：mean anual temperature above 15℃ ，extreme minimum temperature above -10℃，mean an ual precipitation exceeds 1 000 mm ， and the number of months with precipitation less than 50 mm not exceed 5 months． Climatic factor analysis indicates that the temperature is the first principal component afecting the survival and the distribution of this species， while comprehensive efects of temperature and precipitation are the second and third components which afect the growth of the plant.