A series of scientific expeditions in Indonesia for collecting informations and materials concerning locally used medicinal plants and Javanese traditional medicine "jamu" have been carried out by us since 1985. This article reviews pharmacochemical investigations of nine Indonesian medicinal plants: i.e. Pongamia pinnata (Papilionaceae), Fagara rhetza (Rutaceae), Calotropis gigantea (Asclepiadaceae), Beilschmiedia madang (Lauraceae), Caesalpinia major (Fabaceae), Peronema canescens (Verbenaceae), Taxus sumatrana (Taxaceae), Alyxia reinwardtii (Apocynaceae), and Merremia mammosa (Convolvulaceae), which were selected among plant materials collected in those surveys.