Abstract: Objective To investigate drug resistance characters and risk factors among patients with virological failure taking first-line antiviral treatment with drug resistance. Monitoring drug resistance (DR) and providing strategies for ART effects. Methods In-house DR was tested to determine the subtype of HIV-1 in patients with virological failure. The study was a cohort study and subjects were patients with virological failure who emerged drug resistance for first time in 2013-2014. Patients' information was collected from the sub platform of China's legal information management system. The ratios of DR in different factors groups were analyzed using χ² test, and binary Logistic regression was used to analyze the influencing factors of drug resistance mutation. Results The number of patients in this study was 404. The prevalence of DR among virological failure patients taking first-line antiretroviral therapy (ART) was 53.96% (218/404). Patients with treated duration of 2-4 years were at higher DR risk (OR=1.96,95%CI:1.18-3.25). The main DR class was nucleoside reverse transcriptase inhibitor with non-nucleoside reverse transcriptase inhibitor(NRTI+NNRTI)combination, 73.39%. DR mutations distributed in NRTI associated mutations, mainly 184V(79.27%)and NNRTI associated mutations, mainly 103N(35.21%), 181C (32.39%)and 190A(26.29%). Conclusions It is important to maintain success of ART through strengthening early following up on patients after ART initiation, improving adherence to drug, delaying and controlling DR emergence in virological failure patients taking first-line antiviral treatment.