The ecological aspects of kluwak/pakem tree (Pangium edule Reinw) were observed at three location namely Pakeman, Sumber Salak and Sumber Gadung, Sub section II of Conservation Regional Office, Ambulu-Meru Betiri National Park, East Java in October-December 2006. Three transect line measuring 20 m x 1000 m were established accrossed the slope in which observation plots were set up by employing purposive random sampling procedure. The result showed that most of Pangium habitat was found in steep area along the river. Association around the kluwak/pakem trees includes besule trees/Chydenanthus excelsus Miers. Important Value Index (IVI) 28.5%, and wining trees/Pterocybium javanicum R. Br. (IVI 20%). However, wining trees was the most closest association with Pangium vegetation. Biophyisical information of the Pangium vegetation were as follows: 24-30oC daily temperature, 50-80% humidity, 10-65% slope, and 15-306 m altitude. The soil is Latosol with pH 5.5-6.5. Harvesting of fruit of Pangium trees by community surrounding the forest had no negative impact to the trees but this activity should be managed accordingly to avoid disturbing tree generation.