The diversity of bird species is of special importance as it can create responsive and adaptive behaviours among the whole animal population in wild environment. For this reason, the frequent making of inventory lists of bird species helps assess and evaluate the current status of forest resources in natural conservation areas which are inherently under human pressures in our country. During the two years (2009 - 2010) of the study conducted in Huu Lien Nature Reserve in Lang Son province, records have been made of 168 bird species belonging to 117 genus, 54 families, 17 orders. Of these, 9 bird species are rare and of high value of genetic preservation. Discussions have been held on ...