Abstract:The populations of Castanopsis eyrei collected from Daanyuan plots in Wuyishan city, Fujian province were divided into 3 generations according to the size class, i.e. adults, juveniles, seedlings. A total of 92 alleles were detected with 14 pairs of SSR primers, and a mean of 6.571 4 alleles were detected with per pair primer. The mean effective number of alleles (Ae) and expected heterozygosity (He) at population level were 3.905 4 and 0.722 9, respectively. These data suggested that the genetic diversity of C.eyrei was quite high. SSR analyses showed that the highest effective number of alleles (Ae), expected heterozygosity (He), Nei index, Shannon information index were detected in seedlings, juveniles took the second place and the lowest were detected in adults. The most rare alleles was found in seedlings. It suggested that the trend of genetic diversity of the population of C.eyrei was in ascension. Analysis of molecular variance (AMOVA) showed that the genetic diversity might exist within and among different generations of C.eyrei populations, but mainly exist within generations. SSR analyses showed that gene differentiation coefficient (Fst) among generations of C.eyrei populations was 0.074 3 while the gene flow (Nm) was 3.115 4. The genetic identity between adults and seedlings was the lowest. The genetic distance between adults and seedlings was the highest. Based on the analysis of SSR, establishment of nature reserve and conservation of the rare alleles in seedlings and adults is of great importance.