dc.description.abstract | The study of ecology for known peat swamp forest vegetation composition and structure were carried out. Two plots, 0.1 and 0.24 ha each, were placed in ex HPH (Concessionaire) PT. Dexter Timber Perkasa (DTP, Bengkalis regency), and ex HPM-PT WIrakarya Sakti (WKS, Kampar regency), Riau Province, on August 1997. At ex HPH-PT. DTP plots, there were I3 trees species with the density of 530/ha, and basal area 38,03 m2/ha. Three species of dominant trees were Shorea teyst?znlzniana with Important Value (IV)= 36,01%, Calophyllum soulattri (IV= 35,48%), and Palaquiunz burkii (IV= 32,40%). Whereas at ex HPH.PT. \VKS plots, there were 28 trees species with the density of 1058/ha, and basal area 36,86 m2ha. Three species of dominant trees were Calophyllurn soulattri (IV= 45,59%), Slzorea uliginosa (IV=42,58%), and Acronyclzya porteri (IV= 20,44%). Although both habitat were similar, the communities in two plots were different, expressed by small of Index of Similarity (IS= 36,05%). Palaquiutn burkii and Stemonurus scorpioides had a good generation in plot ex WPH.PT. DTP, whereas at ex HPH.PT. WKS plot, the species which had good regeneration were Ilex macrophylla, Mansifera grgfithii, Eugenia clavifZora, and Palaquium burkii. Gonystylus banca~zus and G. mncrophyllus were rare species founded in two locations of study | id |