Dolly Sojuangan Siregar: Inventory of degredation level and carbon stock in protected mangrove forest Kuala Langsa, Aceh. Supervised by Mohammad Basyuni and Siti Latifah. The purpose of this study was to find out accurate data on mangrove species diversity, carbon stock and level of degredation of protected mangrove forest Kuala Langsa which refers to the Guidelines for Identification of Critical Areas Inventory and Mangrove Department of Forestry Directorate General of Land Rehabilitation. A research location in Kuala Langsa Mangrove Forest is geographically located at 97º 53 '15 "- 98º 04' 42" East longitude and 04º 24 '35 "- 04º 33' 47" North Latitude. The survey used to inventory mangrove forest is purposive random sampling method, taken random starting from the sea front towards to the deepest zone. Vegetation study using 3 plots containing 14 lines with a width of 20 m to 190 m length of the line, the distance between plots was 10 m. Measurements made of the tree was a woody plant with Ø ≥ 10 cm (20 m x 20 m), saplings were higher than 1,5 m up to Ø <10 cm (5 m x 5 m), and seedlings were to as high as 1,5 m (2 m x 2 m) Results of this study showed that Rhizophora apiculata dominated either type of seedlings, saplings and trees with the number density of seedlings were 11011,90 individuals/ha, density of saplings were 3009,52 individuals/ha, and density of tree were 70,83 individuals/ha. Total tree biomass was 19.062,68 kg/ha, with carbon stocks of 9,53 tons/ha. Total value score criticality level of protected mangrove forest Kuala Langsa was 285(standard value of non degraded was < 300) resulted this area was degraded. 107001015