Based on analyzing the typical sampling sites in the irrigated area in the north Tarim Basin in different periods and the data from the Second National Soil Survey and agricultural information of this area,the storage and density fluctuation of soil organic carbon content was analyzed by Arc GIS so as to reveal the evolvement of cropland soil organic pools and analyze the relevant affecting factors of soil carbon sequestration in the oasisization process of the irrigated area in the north Tarim Basin. The study was aimed at providing the scientific guidance to improve the soil quality,increase the crop yield in the irrigated area,provide the theoretical support for carbon estimation in Xinjiang and even in north China,and serve for national climate negotiations. The results are as follows: ① The capacities of carbon sequestration for different soil types in cropland were quite different,and the organic carbon content was in an order of meadow soil > solonchak > fluvo-aquic soil > Aeolian sandy soil. On the scale of soil profile, the organic carbon content was decreased from epipedon to bottom,and that of epipedon was up to 2 - 8 g· kg~(-1); ② The average organic carbon densities at depths of 0 - 20 cm and 20 - 40 cm were (1.36 0.09) kg· m~(-2) and (1.10 0.07) kg·m~(-2) respectively,and the organic carbon density for Aeolian sandy soil was much lower than the average; ③ Compared with the 1981s,the change of soil organic carbon density in the study area in 2011 was not significant,and the carbon sequestration rate was in the range of - 0.01 - 0.03 kg·m~(-2)·a~(-1). However,there was a remarkable difference of organic carbon density among different soil types. Holistically,the soil organic carbon content in cropland in the region was increased in the oasisization process,and the main factors affecting the change of soil carbon content were the agricultural practices and reclamation duration.