A total of seventy-nine bird species were recorded in a survey from December 2009 to December 2010 in urban forest of Ya'an. Avian diversity and evenness index were calculated by season, habitat and time period. The value of Shannon-Wiener Index for avian diversity was lower in summer and winter by season, and in farmland by habitat. The dominant species of birds were Paradoxornis alphonsianus, Pycnonotus sinensis, Aegithalos concinnus, Garrulax sannio in the study area. Dicrurus hottentottus, Garrulus glandarius, Parus major and P.monticolus had the highest value in niche wideness calculated based on perching sites. Species composition and habitat of birds in Ya'an have changed significantly since 1960s.