Abstract: Camellia japonica is an important horticultural and economic species，mainly distributed in East Asia. Inter-simple sequence repeat（ISSR）markers were used to investigate the genetic diversity within and among the ten natural populations of Camellia japonica. A total of 210 discernible loci were obtained for all populations using 20 primers，90% of which were polymorphic（PPL = 90%）. The average value of Nei’s genetic diversity and Shannon information index of ten populations were 0.2732 and 0.4003，indicated that the genetic diversity of Camellia japonica populations was relatively high. Population in Kagoshima，Shikoku Island and Goto Island had a higher level of genetic diversity than that in Zhoushan Islands and Changmenyan Island. The value of differentiation（Gst = 0.2028）affirmed that Camellia japonica had high genetic differentiation among populations，and a significant correlation was found between genetic distance and geographic distance（r = 0.9081，P < 0.05）. UPGMA showed that CMY population had a close relationship with Zhoushan Islands populations.

Key words: Camellia japonica, ISSR, island, genetic diversity