The western Tianmu Mts. are situated in the north-west of Zhejiang province The southern slope of Tianmu is opposite the Qiantang River, the vartical differentiation of the climate, vegetation and soil is quite evident. It can be divided into four vertical zones:Ⅰ. Subtropical evergreen broad-leaved forest in wet, hot piedmonts and hills-red earth zone (200-500m a.s.1);Ⅱ. The mixed woods of subtropical evergreen broad-leaved and deciduous broad-leaved forest in the warm hillside-zone of red-dish-yellow soil (500-1100m a.s.1.);Ⅲ. Subtropical deciduous broad-leaved forest in medium Mts.which is cold in winter and hot in summer-zone of yellow-brown soil (1100-1300m a.s.l);Ⅳ. Subtropical bush-wood at the Summit of Mts. cold in winter but cool in summer-zone of yellow-brown soil (1300-1500m a.s.l)The southern slope of western Tianmu was defined as national protection region in 1956. The region is not only a science spot but also used lor the research on plant species, and its natural vertical zones on southern slope belong to a wet mid-subtropics northern edge type. Its woods and plant cover are an integrated ecological system. The region has become the base of scientific research and experimentation.It is an important way to make further development on summer resorts and Sanatoriums. Hence, the urgent task is strengthening the management, and protecting its natural environment as well.