Abstract: This paper studied the heredity variation of seed bearing coefficient.The statistic data were collected from 73 Cunninghamia lanceolata (Lamb.)Hook.seed orchards clones located in Anhui,Fujian and Guangdong(SBC was represented by the ration of tree crown superficial area with cone to total tree crown puperficial area).The results indicated:the difference of SBC among the 73 clones is very significant,interms of genotype variance componemt,in SBC take 33.48%～61.05% of the total varianc and SBC repeatability of the single tree is 0.335～0.611 and of the clones is 0.602～0.825,which indicates that SBC is controlled by moderate genetic controlling and these clones can be reselected efficiently by using SBC as a standard of the seed productivity.