Abstract: The seed yielding stability(SYS) is one of the most important factors affecting seed production in high-generation seed orchard of Chinese fir. Lots of the researches on crop variety stability have been done while only few of seed yielding stability in forest was reported.Exploring the seed yielding stability of Chinese fir seed orchard provides the important basis for re-selecting clones in high-generation seed orchard.There are 25 clones,introduced from Yangkou Tree Farm,Fujian Province,in seed orchard of Chinese fir in Xitian Tree Farm,Anhui Province,which 6 trees were regarded as sample ones in every clone,and seed yielding quantity of these trees was inspected during the 6 years continually.Based on the investigated data,the heredity and variation of seed yielding stability in Chinese fir were discussed in this paper.The results showed that the environmental factors were the key elements to affect seed yielding stability of Chinese fir orchard in the different years,which make up 36.72% of the total variance while Chinese fir clones only account for 10.12% of the total variance.However,the key factor affecting seed yield in Chinese fir orchard was clone genotype in the same year.By means of the variation coefficient of seed yield(cv)or ecovalence coefficient of seed yielding stability,the 25 clones of Chinese fir could be divided into three groups,eg.High-stable,mid-stable and low-stable and nine seed bearing types.The results in the paper would provide an important basis for re-selecting clones in the next generation seed orchards.