Abstract: Samples of 63 seed sources from all the distributed areas of Chinese fir were collected at random and examined. The methods for esterase pattern segregation and development were modified in accordance with Mayberry’s. The results observed were as follows:1. The esterase patterns of 63 seed sources of Chinese fir examined can be divided into seven types of variations. It seems that the variations in ester ase patterns reflect and represent the genetic variations of the trees.2. There is a certain dominant specific type of isozyme in each main centre of culture and the variation of isozymes types tends to be simplified. On the other hand there are more variations of patterns of esterase isozymes in the scattered culture areas. The west and southwest part of Sichuan province, the southeast part of Yunnan province are centres of genetic polymorphism of Chinese fir which might be among the places where Chinese fir originated.