The culture inherent in the Dayak Benuaq community, one of whom lives in Intu Lingau Village, is to plant lembo (fruit gardens) around settlements. The aim of this research is to estimate biomass potential, carbon reserves and uptake, as well as oxygen production in Lembo durian and secondary forests of different ages in Intu Lingau Village, Nyuatan District, West Kutai Regency, East Kalimantan Province. Three research plots each measuring 20 m × 20 m were created in four locations, namely old secondary forest, young secondary forest, old Lembo durian and young Lembo durian. Biomass and carbon stocks in old secondary forests (113.42 and 53.62 tonnes/ha), young secondary forests (49.57 and 23.30 tonnes/ha), old durian lembo (114.07 and 53.62 tonnes/ha). ha), and young durian lembo (65.35 and 30.71 tonnes/ha). The potential for carbon dioxide absorption is 195.47; 85.43; 196.61; and 112.64 tonnes/ha in old secondary forest, young secondary forest, old lembo durian and young lembo durian. Old lembo durian and old secondary forest produce more oxygen (33%) than young lembo durian (19%) and young secondary forest (15%). Information about carbon stocks and oxygen uptake in lembo durian and secondary forest can be used in carbon trading calculation and forest land management in general.