Objective: To generate and identify the mammary gland Scrib gene specific knockout heterozygous mice by Cre-LoxP recombination system, for the research of the role of the Scrib gene on breast cancer at the whole animal level. Method: The heterozygous Scrib conditional knockout was generated and identified. The positive offsprings were mated with MMTV-Cre homozygous mouse, which express Cre recombinase in mammary epithelial cells. The gene type of the offsprings were identified. Results: The genetation of the Scrib heterozygous mice and MMTV-Cre mice were successful and Scrib /fl mouse were identified. 5 Scrib /fl;MMTV-Cre /- mouse were acquired through mating Scrib /fl mouse to MMTV-Cre mouse. Conclusion: Generation of mammary epithelial cells Scrib gene knockout heterozygous mice by Cre-LoxP recombination system was successful, which can supply a novel animals model for further research of the polarity protein Scrib down-regulation on breast cancer．