The identified plants, which were collected during the study of eastern lowland gorillas (Gorilla gorilla graueri) and chimpanzees (Pan troglodytes schweinjurthii) in Kahuzi-Biega National Park, Zaire, from 1987 to 1991, are listed. Kahuzi-Biega National Park includes lowland forest and montane forest, both of which are inhibited by gorillas and chimpanzees. This paper lists 329 species belonging to 83 families that occurred in a two study areas. 118 species were collected in the Kahuzi region (at an altitude of 1,800 to 2,600 m ) and 220 species in the Itebero region (at an altitude of 600 to 1,300 m). Only 9 species were collected in both regions. The food plants of gorillas and chimpanzees (200 species belonging to 69 families), and trees with diameters of 10 cm at breast height or more were collected intensively. For each plant species, the life form, vernacular name (kirega or mashi) and whether apes and/or elephants utilized it as foods, are given. This list is highly biased towards food plants of primates, but provides a preliminary inventory of plants to compare with other study sites of great apes.