Abstract: Objective: To breed and identify aquaporin-3 (AQP-3) gene knock-out mice. Methods: Heterozygote mice were bred and reproduced. Wild genotype, heterozygote genotype and homozygote genotype would appear in the offsprings of parents. Genome DNA extracted from the murine tails was subjected to PCR for genotype identification. Male homozygote mice were selected to mate with the female heterozygote mice to acquire homozygote baby mice according to Mendel law. Results: The breeding and reproducing were successful and more heterozygote genotype mice were reproduced. Conclusions: Appropriate methods of breeding, reproducing and identifying are effective ways for acquiring AQP-3 gene knock-out mice from heterozygote mice.