Abstract: The inter\|simple sequence repeat （ISSR） molecular marker technique was used to investigate genetic diversity， genetic variation to 2 wild stocks and 3 breeding strains in Hizikia fusiformis of south Zhejiang. The results showed that: a total of 76 loci and 56 polymorphic loci were obtained from 6 primers which had been screened and P% （the percentage of polymorphic loci） was 74.67%. Neis gene diversity was 0.1823. Shannons information index was 0.2712. The values were higher than the individual level. Population within and between populations Neis genetic diversity calculation level of genetic differentiation （Gst） was 0.5529， the genetic differentiation between populations was greater than the population differentiation. Gene exchange between the populations （Nm） was 03341; Shannons information index showed that the genetic variability and genetic diversity of wild populations were generally higher than breeding populations. Results also showed that after breeding， the traits of each breeding strains tends to be stable. Clustering figure showed that three breeding strains were separated from two wild populations and they presented significant difference after breeding.

Key words: Hizikia fusiformis, ISSR marker, genetic structure, genetic differentiation, genetic diversity