Objective: To establish transgenic mouse lineages containing copies of a stably integratedpSPORT1 plasmid by microinjection into fertilized eggs and to provide an efficient animal model for studyinggene mutations in vivo. Methods and Results: 2594 fertilized eggs from KM white mice were injected withpSPORT1 DNA and transferred into the oviducts of 103 pseudopregnant females. from which 237 offspringswere obtained. 40 of these offsprings were identified positive for the forgeign gene by PCR analysis and 38were reproved positive by Southern blot analysis. Finally, eight of the stout mice whose genornes were integrated with intact pSPORT1 vectors, verified by Southern blotting analysis, were chosen as founders to establish the transgenic mouse lineages. The experimental results inchoated that the pregnant rate of recipientfemales and the Positive rate of offsprings were dramatically influenced by the structure of the transgene(linearized or circular ) and the mode of egg-transfer. The integration rate of linearized transgene was significantly higher than that of the circular transgene,and female with two-side oviduct transfer of fertilized eggs waseasy to have baby mice. Conclusion: (1 ) Transgenic mouse lineages containing copies of a stably integratedPSPORT 1 plasmid were established; (2 ) The linearized transgene and two-side oviduct transfer of fertilizedeggs is more efficient in preparing transgenic mice. Objective: To establish transgenic mouse lineages containing copies of a stably integrated pSPORT1 plasmid by microinjection into fertilized eggs and to provide an efficient animal model for studyinggene mutations in vivo. Methods and Results: 2594 fertilized eggs from KM white mice were injected with pSPORT1 DNA and transferred into The oviducts of 103 pseudopregnant females. from which 237 offspringswere obtained. 40 of these offsprings were identified positive for the forgeign gene by PCR analysis and 38were reproved positive by Southern blot analysis. Finally, eight of the stout mice whose genornes were integrated with intact pSPORT1 vectors, verified by Southern blotting analysis, were chosen as founders to establish the transgenic mouse lineages. The experimental results inchoated that the pregnant rate of recipient females and the Positive rate of offsprings were dramatically influenced by the structure of the transgene (linearized or circular) and the mode of egg-transfer. The int egration rate of linearized transgene was significantly higher than that of the circular transgene, and female with two-sided oviduct transfer of fertilized eggs waseasy to have baby mice. Conclusion: (1) Transgenic mouse lineages containing copies of a stably integrated PSAPORT 1 plasmid were established ; (2) The linearized transgene and two-sided oviduct transfer of fertilizedeggs is more efficient in preparing transgenic mice.