Abstract: In the winter of 1982,there was severely cold weather that seldom occured in the history of Yunnan.As a resnlt,it caused frost injury to various forest trees.Through field surveys and laboratory tests on the species-resistance to frost,it was found that,besides some exotic species,native species such as Alnus nepalensis also suffer from frost seriously.The authors suggest that the following points be discussed,i.e.reasonable distribution of the forest tree species,selection and breeding of the frost resistant species,treatment for Eucalyptus suffering from fro.st injury of third grade up.