Abstract: The Chinese fir is an important forest tree of South China,it has been under cul- tivation for a long time.With the object to increase its growth rate and cut short rotation period,we made inter-generic crosses reciprocally between Cunninghamia and Cryptomeria since 1955.Inspite of their morphological differences,they were cross- compatible and fertile with each other.The F_1 hybrids showed different degrees of heterosis as compared with their parent species and material inheritance,whether they will segregate or not needs further investigation.In the fall of 1959,we found one of the cryptomeria hybrids set forth a shoot with comparatively flat needles,which were quite different from the rest,they were linear-lanceolate,rather than awl-shaped,with two resin ducts. At the same time we also made intra-specific crosses between trees from different localities.The hybrids also showed certain degrees of hybrid vigour.It suggests to make systematic crosses within the species by selecting elite trees from different regions for propagation and breeding materials.The best trees should be selected to establish seed orchard to produce seeds for planting. The whole report deals with technic of crossing,growth rate of hybrids,and the inheritance of the character of viridis of the race of cryptomeria.