Wulandari, SriSuwondo, SuwondoNursal, NursalCasther, Casther2018-04-032018-04-032018-04-03978-602-51349-0-6wahyu sari yenihttps://repository.unri.ac.id/xmlui/handle/123456789/9339This study was conducted to determine the estimation CO2 absorption in the arboretum Riau University. The method used is purposive random sampling by considering the condition of vegetation and topography. The research parameters were: (1) vegetation analysis; (2) carbon stock and (3) CO2 absorption. Vegetation of trees in the arboretum Riau University has 25 family, 44 species and 604 individuals with average density of 55.26 ind / ha, frequency average of 8.48, average dominance of 10.66 m2 / ha, and the average diversity index of 2. 94 with medium category. The most important tree species in absorbing CO2 is Hevea brasiliensis of 0.51 ton / ha. Total carbon reserves of 1.12 tons / ha and CO2 uptake of 4.11 tons / ha. With an arboretum area of the University of Riau ± 10 ha then the absorption of CO2 that occurs is 41.1 tonsenArboretum CO2 Absorptiontree vegetationArticle