, the most valuable prawn species, plays an important role in aquaculture in China, so protective measures must be taken to ensure its normal reproduction. In this study, we measured the genetic diversity and genetic structure of 135 individuals collected from a before-release population (FLQ), an after-release population (FLH), and hatchery postlarvae population (FLXX) by sequencing the 938 bp mitochondrial D-loop. D-loop is a non-coding sequence which locates in the noncoding region of the mitochondrial genome. Overall, we detected 237 variable sites, 177 parsimony-informative sites, and 100 haplotypes. The nucleotide diversity index (0.02480) and haplotype diversity index (0.993) of the before-release population were higher than the nucleotide diversity (0.02125) and haplotype diversity (0.960) of the hatchery postlarvae, and slightly lower than the nucleotide diversity index (0.02394) and haplotype diversity index (0.993) of the after-release population. The genetic distances within population of the three groups were 0.02598, 0.02504, and 0.02216, respectively. The genetic distance between the released postlarval and before-release populations was 0.02582; that between the released postlarval and after-release populations was 0.2524; and that between the before-release and after-release populations was 0.02567. Analysis of molecular variance showed that for the before-release population and after-release population was 0.00629 ( > 0.05), so that most variation was within each population, although the finding was not significant. Between the hatchery postlarvae and the after-release population, < 0.01), so the genetic variation coefficient between groups was 8.15% and the genetic variation within the populations accounted for 91.85%, indicating that most genetic variation occurred within the populations, and the genetic differentiation among the populations was low. In neutrality tests, the values of Tajima's were negative, with deviations from the neutral mode, indicating that has been subject to population expansion and natural selection. In summary, proliferation activity not only maintains resources, but also the genetic structure of a population, which ensures that the after-release population retains a high level of genetic diversity.