Soil organic carbon (SOC) is an important indicator to measure the land desertification. Yulin city is taken as a case to study the SOC dynamics of desertification rebuilding area in a local scale. The data source based on the second soil survey in year of 1982 and repeated soil sampling in year of 2003

and the methods for sampling

determining and analyzing of SOC are auger hole method

K_2Cr_2O_7 oxidation method

area-weigh method respectively

and micro-pipette method is used to determine soil texture. The main conclusions are as follows: SOC content is much correlative to soil texture

it is negative correlation to coarse silt(R=-0.50

a=(0.01)) and positive correlation to clay(R=-0.45

a=0.05); The content

density and storage of SOC in original profile

1 m depth and arable layer increase greatly during the 20 years

among which the arable layer is most remarkable result in direct and indirect mankind activities; The content

density and storage of arable layer SOC are increased by 0.55 g/kg

0.15 kg/m~2

10.07GgC respectively

which representing rate of increase of 21.00%

(33.02)%

33.02% correspondingly. The results show that tree and grass planting

return plantation to woodland or pasture

sustainable agricultural managements and other countermeasures will promote desertification reverse significantly

which will helpful to increase the amount of SOC and carbon sequestration in desertification area.