Abstract: According to the analysis of stand level rate,this paper presented the storey index after studying the method that can improve stand level rate,and the new parameter was applicatied for the storey structure study of Cyclobalanopsis myrsinaefolia mixed stand in Longhushan forest farm of Hunan. The practical study indicated that based on keeping many characteristics of stand level rate such as simpleness,good promises,easiness to obtain data,the storey structure expressed the diversity of storey structure,and it could describe the vertical distribution pattern of stand better. The analysis showed that the order of the three sample plots of Cyclobalanopsis myrsinaefolia mixed stand 's storey structure from complex to simple was: P2>P3>P1,and the analysis of species showed that: Cyclobalanopsis myrsinaefolia was the most stable,its regeneration was fine; Quercus fabri was stable,but its understorey was harmed in some place by natural or artificial factor; Liquidambar formosana and Castanopsis sclerophyllus didn't have understory,their regeneration is bad,they need to be protected,and keep growing by human's help.

Key words: stand level rate, storey index, Cyclobalanopsis myrsinaefolia