Some rain and savanna forests of western Suriname (Corantijn R., Winana Creek; Upper Marataka R.; Upper Nickerie R;) were studied and their composition was compared with that of forests of other parts of Suriname and Guyana. The savanna forests of western Suriname proved to be much related to Guyanan ( Walabaand Dakama-) savanna forests as described by Davis & Richards (1934) and Fanshawe (1952). On the other hand, there was less relationship as regards rain forests of western Suriname when compared with ones of Guyana and other parts of Suriname, except for the Demerara greenheart forest of the Upper Marataka R., which was closely related to the Demerara greenheart forests of Guyana as described by Davis & Richards (1934). In addition an upland rain forest was studied near Blanche Marie falls, Upper Nickerie R., which proved to be very much like that of the Stofbroekoe Mts., eastern Suriname, as described by Schils (1960). Species/area curves for some rain and savanna forests are given. The geographical distribution of some common western Surinam tree species was studied; of the seventeen species studied one was endemic for Suriname. An annotated list of all species of trees and palms occurring in the explored areas is provided.