Abstract: Many batches of Litopenaeus vannamei were introduced to China and used as broodstocks to reproduce relatively independently. Analysis on genetic diversity of six cultured stocks in south China revealed that genetic diversity level of the stock introduced from Hawaii was relatively high, and Dongfang, Haixing and Xuming stocks were close to the introduced one. Genetic diversity level of Qiantang stock was the highest compared with that of Dongfang, Haixing, Xuming, and Guangyi stocks, suggesting that Qiantang stock was contaminated by other stocks. Genetic diversity level of Guangyi stock was the lowest, suggesting inbreeding depression. Genetic distance among stocks was evaluated and a dendrogram tree was constructed using UPGMA method, which could be useful for selection of distant broodstocks for outbreeding in the near future.