Suwi River, which is a part of Kenohan-Suwi Wetland in East Kutai District, East Kalimantan is a habitat of endangered animals such as proboscis monkey (Nasalis larvatus). Therefore, this study aims to determine the habitat, distribution, threats, and conservation efforts of proboscis monkeys in the Suwi River. To achieve this, the boat survey method was adopted, while plot line samples were used for vegetation analysis. The results showed that the habitat is composed of riverine plant species, such as prupuk (Mallotus sumatranus; IV=121.84%), bungur (Lagerstroemia speciosa; IV=37.10%), and rengas (Gluta renghas; IV=34.76%). Furthermore, a minimum of 12 monkey groups was distributed in this area, however, their population is unknown. Illegal hunting by local people has caused population decline, this is in addition to other threats, such as habitat conversion, forest fire, and invasive plant species. The effort to protect the habitat of proboscis monkeys was made by developing Essential Ecosystem Areas Suwi-Mesangat. Other institutions that committed to protecting this area include Federal and local government, NGO, local community, and palm oil company