The problems to be solved by the present invention are to provide: a recombinant varicella-zoster virus a process for producing the same a pharmacological composition containing a recombinant varicella-zoster virus a vector containing a BAC vector sequence in the specific gene of a genomic gene of varicella-zoster virus cells containing such a vector a fragment capable of homologous recombination with a genome of varicella-zoster virus a nucleic acid cassette containing the BAC vector sequence and a multivalent vaccine. The above problems were solved by developing a process for producing a recombinant varicella-zoster virus, wherein the BAC vector sequence is inserted into a specific virus gene.