Emerging HIV drug resistance (HIVDR) poses a growing threat to the long-term success and durability of highly active antiretroviral therapy (HAART). To understand the incidence of HIVDR and estimate the proportion of potential HIVDR and its associated risk factors among the patients on HAART for one year. Antiretroviral-naïve patients ≥ 18 years old were invited to participate in this one-year prospective study from seven clinics in Yunnan, Guangxi, and Xinjiang provinces. A questionnaire and blood draw were collected at baseline and 12 month follow-up. The protocol used was modified slightly from the WHO Protocol for Surveys of HIV Drug Resistance Emerging During Treatment and Related Program Factors in Sentinel ART Sites in Resource-limited Settings. 435 subjects were included in the final analysis, with median baseline CD4 cell count 139 cells/mm3. Of the total 417 patients who fall under WHO guidelines for 'Classification of outcomes based on endpoints' (on ART at 12 months, switch, lost to follow-up, and stop), 90 (21.6%) did not have any drug resistant mutations (potential HIVDR) and 17 (4.1%) did (HIVDR, Table 2). The remaining 310 (75.3%) had a viral load <1000 copies/ml (HIVDR prevention). Among 351 patients retained at 12 months, 41 (11.7%) had a viral load >1000 copies/ml.Patients who self-reported missing doses in the previous month were 6.2 fold (95% CI 2.5-15.7) more likely to fail than those who did not. and those from Xinjiang were 12.1 fold (95% CI 5.2-28.1) more likely to fail compared to those from Yunnan and Guangxi. Why Xinjiang was associated with virologic failure was not clear but may be related to the demographics of the participants from Xinjiang, being significantly more IDUs, poorer, and less adherent than those from Yunnan and Guangxi. Although successful virologic outcomes were seen in the vast majority (75.3%) of those treated at one year, virologic failure continues to be a problem particularly among those less adherent and from Xinjiang. Additional data are needed to understand the generalizability of these results, particularly those related to Xinjiang. For IDUs, enhancing adherence to HAART and considering the treatment of drug addiction as an integral part of the treatment for HIV infection should be considered. As China's National Free Antiretroviral Treament Program continues to mature and improve, ramping up treatment in these settings may be important considerations to the long-term success of the program.