Background:　Persistent　human　papillomavirus　(HPV)　infection,　especially　with　high-risk　types　such　as　HPV16　and　HPV18,　has　been　identified　as　the　primary　cause　of　cervical　cancer.　E6　and　E7　are　the　major　onco-proteins　of　high-risk　HPVs,　which　are　consistently　expressed　in　HPV　infected　tissues　but　absent　in　normal　tissues　and　represent　ideal　therapeutic　targets　for　immunotherapy　of　cervical　cancer.　Materials　and　Methods:　In　this　study,　the　optimized　fusion　gene　HPV18　E6E7　(HPV18　ofE6E7)　was　constructed　according　to　genetic　codon　usage　for　human　genes.　At　the　same　time,　for　safety　future　clinical　application,　a　mutant　of　HPV18　ofE6E7　fusion　gene　was　generated　by　site-directed　mutagenesis　at　L52G　for　the　E6　protein　and　C98G　for　the　E7　protein.　Results:　HPV18-E6E7　mutant　(HPV18　ofmE6E7)　constructed　in　this　work　not　only　lost　the　transformation　capability　for　NIH　3T3　cells　and　tumorigenicity　in　BALB/c　nude　mice,　but　also　maintained　very　good　stability　and　antigenicity.　Conclusion:　These　results　suggest　that　the　mutant　should　undergo　further　study　for　application　as　a　safe　antigenspecific　therapeutic　vaccine　for　HPV18-associated　tumors.