This paper presents a survey of beneficial hymenopteran groups in the buffer zone of Cuc Phuong National Park (NP). The conservation importance of the social bees and wasps and the hymenopteran parasitoids of the families Braconidae, Ichneumonidae, and Scelionidae are also elucidated. The survey was conducted in 2001-2003 in the buffer zone in order to reveal assemblages of beneficial hymenopteran wasps. Species composition, conservation importance, and use value of beneficial hymenopteran groups, as well as environmental and habitat conditions were analyzed. Populations of 30 social vespid wasps (Vespidae) were compared from the buffer zones of three National Parks (NPs) in Northern Vietnam, namely, Ba Vi, Cuc Phuong, and Tam Dao National Parks (NPs). Of the 30 social vespids recorded from three protected areas, there were six, six, and 11 species found in Ba Vi, Cuc Phuong, and Tam Dao NPs, whereas, 16, 20, and 20 species were commonly found in the buffer zones of the three NPs, respectively. Obviously, in the buffer zone, social vespid wasps are more diverse and predominant than in the NPs themselves. Habitats with a natural cover of shrubs and bushes in the buffer zone are not only suitable nesting sites for many social aculeate wasps but provide a food source for these wasps as well. The inventory of 85 plants which provide nectar, pollen, and both nectar and pollen for honey bees which include Apis cerana, Apis dorsata, and Apis florea indicated a high potential for the development of beekeeping in the buffer zone of Cuc Phuong NP. In the buffer zone, 46 important hymenopteran parasitoid species were reared from the target insect pests infesting wet rice, soybeans, maize, and sugarcane that have only one crop in the rainy season from May through October. Of these parasitoids, 22 species of Braconidae, 17 species of Ichneumonidae, five species of Scelionidae, and one species of Eupelmidae are considered as potential agents for biological control of agricultural insect pests in the buffer zone. Four parasitoid species found in the buffer zone of Cuc Phuong NP but not in the lowlands are Stenobracon niceviIlei, Pseudoshirakia ( = Tropobracon) yokohamensis, Cotesia flavipes (Braconidae), and Ischnojoppa luteator (Ichneumonidae). Of these braconid species, Pseudoshirakia yokohamensis is newly recorded for the fauna of beneficial hymenopteran wasps in Vietnam. All the four parasitoids are thought of as having high potential for biological control and the economic savings due to hymenopteran parasitoids are substantial. The activity of parasitic hymenopteran species is so effective that pesticides do not need to be sprayed to protect rice, soybeans, and maize, and the use of pesticides has been considerably reduced for pest control of sugarcane. Meanwhile,the misuse of pesticides that especially limits effectiveness of the egg parasitoid, Anastatus japonicus, in the natural control of pests on litchi and longan. Apocrita (Hymenoptera) Apoidea (Aculeata) Animals and man; Land zones; Oriental region; Eurasia; Asia Apocrita; Animals and man; Vietnam; Beneficial faunal survey & uses; Cuc Phuong Naional Park Apoidea; Vietnam; Beneficial faunal survey & uses; Cuc Phuong Naional Park none2004