To investigate the genetic stability (including the vector of vaccinia virus and six foreign genes: gp160, gag, pol, rev, tat and nef) of the HIV-1 non-replicating recombinant vaccinia virus (rNTV-C). rNTV-C was serially passaged to passage 25 (P25) in primary chicken embryo fibroblast (CEF). P9, P12, P15 and P25 were selected to study the genetic stability in four aspects, including the genetic stability of viral vector, the genetic stability of six foreign genes, the expressing stability of foreign genes and the genetic loss of foreign genes. The results showed that the viral vector was non-replicated vaccinia virus of Tiantan strain and was passaged stably; foreign gene sequences matched with designed sequences, the insert sites were right, and the nucleotide mutation rate was less than one over ten thousands within different passages of rNTV-C; the target proteins could be expressed effectively, and the expression level was stable within different passages of rNTV-C; the genetic loss of gag and nef was less than 5% within different passages of rNTV-C. The above results provided important data for the vaccine production.