Abstract: With the recent rapid urbanization in China, the carbon and oxygen cycling load in urban ecosystem had been increasing. It is very important to estimate the balance of carbon and oxygen. In this study, we used the data of land use and land cover change(LUCC) and the date from the statistical yearbooks, based on the carbon dioxide emissions model by Chinese Academy of Sciences, we estimated the carbon oxygen balance in Xinjiang, China from 1999-2014. The result showed as follows:(1) the change of cultivated land, forest land and grassland area has a greater influence on the overall land allocation, and the area of every land type was increased steadily annually except the grassland. The areas occupied by the gardens and the land areas for transportation were changed the most;(2) by the end of 2014, the net CO₂ emission accounted for 36.04% of the total fixed amount of carbon dioxide;(3)by the end of 2014, the net O₂ consumption accounted for 32.06% of the total release of O₂;(4) the ecological compensation mechanism has shown a positive effect. The fixed amount of CO₂ was increased by 4.56%, and O₂ emissions were increased by 13.81%. The carbon and oxygen cycle system was in a state of overloaded and unbalanced. Although the negative impact was still weak, but in the long run, it is bound to affect the stability of the ecosystem adversely.

Key words: carbon oxygen balance, model, land change, carbon emission, oxygen consumption, Xinjiang