Objective To investigate the HIV drug resistance among HIV/AIDS patients who had received highly active antiretroviral treatment (HAATR) in Liangshan prefecture and related factors.Methods This investigation was conducted from August to October 2010.Data on epidemiology,treatment,CD4 + T cell,viral load and drug resistance tests were collected.Results 233 (73.50％) had a viral load of ＜ 1000 copy/ml,with the median CD4+T cell count as 329 cell/μl.26 samples appeared to be drug resistant,with the rate as 8.20％.Among 84 patients with antiviral therapy failure,the overall drug resistance rate was 30.95％(26/84).While 24 (28.57％) were resistant to non-nucleoside reverse transcriptase inhibitor (NNRTI) drugs.Among nucleoside reverse transcriptase inhibitors (NRTI),7 (8.33％) were resistant.1 (1.19％) had protease inhibitor (PI)resistance mutations identified.Factors that significantly associated with drug resistance would include:being injecting drug users (A OR =3.37,95 ％ CI:1.06-10.66,P =0.0390),having had chronic diarrhea ＞1 month (AOR=8.38,95％ CI:1.87-37.69,P=0.0055),having had CD4+T cell＜200(AOR=3.48,95％CI:1.29-9.39,P=0.0139),being residents from Butuo area (AOR=17.68,95％ CI:4.97-62.86,P＜0.0001 ).When comparing with other areas,data from Butuo showed that people who carried Yi ethnicity (AOR=17.35,95％ CI:2.01-149.73,P=0.0095) and were literate (having had primary or higher levels of education) (AOR=0.18,95％ CI:0.08-0.42,P＜0.0001 ),being married or having cohabited relations (AOR=8.17,95％ CI:2.35-28.39,P=0.001 ) were found to be less adherent (AOR=0.05,95％ CI:0.02-0.13,P＜0.0001) to the treatment.Conclusion Successful antiviral outcomes were seen among those AIDS patients under treatment,in Liangshan prefecture.Resistance rates were significantly different in regions.For IDUs,enforcement on subjects including prevention on drug resistance,adherence to HAART and treatment for drug addiction should be strengthened and programs being integrated.