A survey of bird diversity was carried out at Tung Salang Luang National Park in three forest types i.e. mixed forest (seasonal evergreen forest mixed with deciduous dipterocarp forest), seasonal evergreen forest and deciduous dipterocarp forest, during March 2004 to February 2005. The point count mixed line transect methods were used for data collection. The survey found 6,697 birds in total from 140 sp., 35 families and 11 orders occurring in the mixed forest, seasonal evergreen forest and deciduous dipterocarp forest were as follows: 107, 100 and 94 sp. The quantitative bird communities have a negative correlation with climatic changes, as a result, the dynamic pattern of bird populations in the 3 habitats during a year were similar. The fewest species numbers and individual numbers were found during the rainy season and slightly high during the late rainy to early cool seasons. The highest bird populations were found during cool season. Similarity index values of birds in both mixed forest and seasonal evergreen forest were the greatest similar, while both mixed forest and deciduous dipterocarp forest were fewest less similar. The 72.6-78.3% qualitative similarity index values of bird species between study sites was done. Mixed forest had the highest Shannon diversity index 3.9507, followed by deciduous dipterocarp and seasonal evergreen forest were 3.6387 and 3.6025, respectively. The pattern observed suggest that the structure and dynamics of the Tung Salang Luang bird community are strongly liked to physical factors and habitat heterogeneity. Two particular species of bird were observed in this study: Aviceda jerdoni (Jerdon` Baza) and Coracina javensis (Javan Cuckooshrike).