Abstract: ObjectiveTo study the serological characterization of indeterminate western blot results of human immunoldeficiency virus(HIV)antibody and to find the causes and the influence of the indeterminacy. MethodsThe data for 302 cases with indeterminate HIV antibody western blot profiles and 61 patients receiving follow-up diagnostic testing in Liaoning AIDS Corroboration Center Laboratory from 2007-2011 were analyzed. ResultsThere were 18 strip types in the 302 cases with indeterminate HIV antibody western blot profiles,with the top three types of p24(43.4%,131/302),gp160 p24(19.2%,58/302),and gp160(18.9%,57/302).HIV showed three main structure antigens,with 12 strip types of env(51.0%,154/302),2 strip types of gag (46.7%,141/302),and 4strip types of pol(2.3%,7/302).Among the 61 cases completing the follow-up detection,16(26.2%)were diagnosed as positive.In the 16 positive patients,strip type of env was dominant(93.8%,15/16).For the 61 cases,the proportion of env type was 59.0%(36/61),with significant difference(χ²=12.103,P<0.05).There were 22 indeterminate strip type of gag showed negative result at the end of follow-up. ConclusionThe results indicates that the most common indeterminate HIV western blot profile is gag protein strip for unspecific reaction and the profile of env has more predictive significance for HIV infection.