Cat Ba National Park is the home of many rare species such as Cat Ba langurs (White-headed langurs, Trachypithecus poliocephalus), chamois, otters, leopards, wild-cats, civets, black squirrels. Specially, the Cat Ba langur is a rare species which has been listed in the most endangered species list and in the Red List of IUCN. However, the conservation and development of the Cat Ba langurs has encountered many difficulties due to the terrain, the awareness of local people, and economic and tourism activities affecting the ecological environment of the National Park. This research uses the following methods: field survey, in-depth interview and Contingent Valuation Method to evaluate the conservation value of Cat Ba langurs in the Cat Ba National Park, Hai Phong city. The research results show that 93% of households agree to pay for conservation of the Cat Ba langurs species with the average willingness to pay of 37,526.88 VND/household/year. The results of the study are the scientific basis which provide the necessary information to build and develop the management recommendations effective and appropriate to local conditions for the conservation of the Cat Ba langurs in the Cat Ba National Park, Hai Phong city.