is a perennial red alga (Rhodophyta) commonly used as a source of food, drugs, or textile industry raw materials. Recently, has been used for artificial breeding experiments and aquaculture research. However, limited genetic information about this species has hindered progress in artificial culture of it. In this study, we estimated genetic diversity in using amplified fragment length polymorphism markers with three populations of 90 individuals from Shenzhen, Shantou, and Changdao, China. Ten pairs of polymorphic primers were screened, generating 427 loci, of which 392 (91.75 %) were polymorphic. Loci obtained from each pair of primers ranged from 30 to 59. The Changdao population possessed the highest number of amplified loci and the highest polymorphism level. The observed number of alleles () showed the same trend in the three populations (i.e., Changdao>Shantou>Shenzhen), suggesting that the Changdao population had the highest genetic diversity. Major genetic variation existed among the populations. was 0.575 4, indicating high genetic differentiation among the populations. The smallest genetic distance was found (0.110 2), while the largest was between the Shenzhen and Changdao populations (0.357 7). The Shenzhen and Shantou populations clustered together and then grouped with the Changdao population, suggesting that the genetic divergence observed was related to geographical distance. Our results resources.