Sago (Metroxylon sago), plant spesies growing on the wetlands has a multiple function. The purpose of this study was to obtain population structure of sagu in the area of Rampah Menjangan Waterfall, Loksado. Data was collected in a path of (2.500 x 20) m. Sagu population was divided into seedling, sapling, pole, and tree. The number of tree individuals was more than this of poles and saplings, but was less than this of seedlings. The structure population of sagu in the research area was not the same as the general structure. Keywords: population structure, sago