【Objective】Carbon fixation benefits were evaluated in 100 thousand mu （6667 ha） emission reduction forests of Karamay City in order to provide theoretical references for forest resources management in Northwest desert areas and other parts of country. 【Method】The carbon fixation value and carbon fixation benefits per unit area of 100 thousand mu emission reduction forest of Karamay area were estimated on the basis of number of trees and their varieties， tree diameter， tree height and canopy area. 【Result】In the Karamay emission reduction forest， the fresh wood volume was recorded as 1.43×106 m3， total biomass was 2.21×106 t， physical quantity of carbon fixation was 3.60×106 t and converted pure C amount was 9.81×105 t. The carbon fixation value was estimated as 2.15×108 Yuan， and carbon fixation value per unit area was recorded as 32250 Yuan/ha. 【Conclusion】The emission reduction forests of Karamay were found to play a very important and positive role in maintaining dynamic balance between CO2 and O2 in biosphere and reducing the effects of global warming.