Study object. Forest stands in Lithuania: pine, spruce, birch, aspen, black alder, grey alder, oak, ash and others. Study aim. To estimate CO2 sequestration, to evaluate and to analyze its dependency on the main tree species, mean annual increment, age. Methodology. The estimations were made according to formulas stated in book “Algorithm of forest resources reproduction model (1984)”. The formulas allow to calculate CO2 stock per hectare in differrent tree species stands according to annual increment. Also by using Willis&Benson method and data based on calculations made by State Forest Survey Institute according to “IPCC Good Practice Guidance for LULUCF” methodology. Results. The biggest amount of CO2 is sequestrated in deciduous forest stands: by Zubas et al. method – 17,5 t/ha/year (coniferous – 14,2 t/ha/year); by Willis&Benson method – 10,3 t/ha/year (coniferous – 8,8 t/ha/year); by IPCC Good Practice Guidance for LULUCF method – 8,8 t/ha/year (coniferous – 7,4 t/ha/year). The age classes where annual increment is the highest sequestrate more CO2 than the ones with a lower annual increment. The total estimated value for the sequestrated CO2 of year 2002 in all the forest stands in Lithuania are as stated: by Zubas et al. method – 2,9 mill. Lt; by Willis&Benson method – 1,8 mill. Lt and by IPCC Good Practice Guidance for LULUCF method – 1,5 mill. Lt. For the warmhouse effect reduction the most valuable are tree species with the least economical value of wood... [to full text]