The expressions of HOXB5, HOXB6, HOXB7, and HOXB8 genes of U251 cell infected by human cytomegalovirus and/or treated with all trans-retinoic acid(ATRA) were detected by semi-quantitative RT-PCR. The results were that U251 cell did not express HOXB5, HOXB6, and HOXB8 but expressed HOXB7 without infecting HCMV and/or being treated with ATRA. After infected with HCMV and/or treated with ATRA, the expressions of HOXB7 and HOXB8 were up-regulated and the expression of HOXB7 lasted the fourth generation, while HOXB8 was up-regulated only in the second generation. These results indicate that the abnormal expression of HOXB gene induced by HCMV may play an important role in the maldevelopment.