Objective To investigate the distribution of HIV-1 subtypes in Dehong prefecture,Ymnan province,in 2011.Methods 300 HIV-1 positive plasma samples were collected from Jan.2011 to May 2011 in Dehong prefecture.HIV-1 gag genes and env genes were amplified by nestedpolymerase chain reaction (PCR) from viral RNA,After sequencing,the HIV-1 subtypes were determined by phylogenetic analysis.Results Based on the phylogenetic trees of gag gene and env gene fragments,a total of 222 samples were genotyped.Subtype C was the predominant strain in Dehong (43.2％,96/222),followed by unique recombinant forms (URFs,27.0％,60/222),CRF01 _AE ( 21.2％,47/222 ),C R F08_BC ( 5.0％,11/222 ),B,( 2.3％,5/222 ) and CRF07 BC ( 1.4％,3/222).Subtype C strains were predominant in both heterosexually transmitted population and intravenous drug users (IDUs),but different subtype distribution patterns were found in these two populations.All 6 genotypes including subtype C (40.7％,70/172),CRF01_AE (25.0％,43/172),and URFs (25.0％,43/172 ) found in this area among hcterosexually transmitted population,which showed the diversity of genotypes in this population.Except subtype B' and CRF07_BC,the other 3 subtypes and URFs were detected among IDUs,mainly including subtype C (54.8％,23/42) and U R Fs (38.1％,16/42),vhich shoved the concentration trend of genotypes distribution among IDUs.The proportion of URFs increased significantly in this area,including the new BC recombinants (41.7％,25/60) and CRF01_AE relative URFs (58.3％,35/60).However,the distributions of these two URFs among heterosexually transmitted population and IDUs showed no statistical significance.Conclusion The distribution of HIV-1 strains prevailing in Dehong prefecture was diversity,including 5 subtypes and a variety of URFs,of which subtype C was the predominant strain.The distribution patterns of subtype were different among different populations.