Abstract: Objective To understand affecting factors in synthesized antineer oviral therapy(ART)in preventing mother-to-child HIV transmission,providing basis for making up measures of rational and canonical medicine using in ART.Methods Qualitative and quantitative methods for measuring use of regimen towards antiretrovirus therapy of PMT CT were used in a case-control study of mothers who received services of PMTCT from January,2005 to March,2007 in 5 HIV epidemic counties.Results Percentage of canonical medicine using in antivirus therapy was 53.2%(84/158).The main correlations with the using combined regimen of ART for positive pregnant women and their infants were as following:the sake of preventing children from infection,the customs of avoiding blood test,traffic,income,health status of HIV positive pregnant women,the knowledge of side effect,confidence of PMTCL.Conclusion Multiple factors affect the using combined regimen for antivirus-therapy in PMTCT.