This study, which covered 352 villages, 44 communes and 11 districts of Hagiang province with 2.914 chicken and lasted from March 2005 to September 2006, was aimed at evaluating the phenotype diversity of local chicken population in Hagiang province. The results showed that chicken in Hagiang had diversified appearances and were distributed in different ecological conditions. The average mature body weight of chicken was around 1.58 kg and 1.76 kg. All phenotypes were obsevered in high soil mountain and high rocky mountain areas (Dongvan, Meovac, Quangba, Yenminh, Hoangsuphi and Ximan). Feather phenotypes included fuzzy feather, smooth feather and striped feather. Fuzzy feather chicken concentrated on high rock mountain areas. Percentage of fuzzy feather and smooth feather chickens was 16.38 and 17.72% in Dongvan, respectively (the average of Hagiang province was only 4.26% and 3.32% respectively). The special black chicken breed reared by HMong ethnic group (black skin, bone, meat) occupied 4.56% and mainly concentrated in Dongvan and Xinman. There were four types of crest: single, rose, pea and strawberry crests. The percentage of chicken with orange, brown and black eyes was 81.45; 16.90, and 1.65%, respectively. Estimated allele frequencies at locus C for C and c+ were 0.753 and 0.247, respectively. Estimated allele frequencies at locus I for I and i+ were 0.041 and 0.959, respectively. Estimated allele frequencies at locus F for F and f+ were 0.753 and 0.247; at locus H for H and h+ were 0.194 and 0.806 and at locus Pg for Pg and pg+ were 0.883 and 0.117, respectively.