Abstract: Castanea heyyi,which is one of the most important economic forest trees in China,has been cultivated for a long time in the north part of Fujian province,especially in Jianou country.However,from the second half of 1990’on,the cultivated areas in these regions have been always increased based on assarting forest sites in existence and grafting propagation.This paper studied the genetic diversity of C.heyyi,and C.sequinii in Jianou using RAPD DNA marker,and made a comparison with varieties of Chinese chestnut from all over the country.The results showed the percent polymorphic loci of C.heyyi(44.9%) was lower remarkably than that of C.sequinii(53.7%) and C.mollissima(52.7%).The further analysis on their effective allele amounts ranged from 1.608 8～1.621 6,Nei’s gene diversity ranged from 0.348 0～0.352 9 and Shannon information index ranged from 0.517 9～(0.535 7),indicated higher genetic diversity in these three species.