This paper was aimed at the distribution and composition of organic carbons in water stable aggregates in typical arable cinnamon soil in Heibei Province. The size distribution of water stable aggregates was as irregular "W" shape with two lower "shoulders". Soil organic carbon content in Gaocheng City (12.49 g/kg)was roughly equivalent to that of Xingtang County(11.20 g/kg). The distribution of soil organic carbon(SOC) in soil was predominately constrained by the allocation of aggregates. Organic carbon in preponderant aggregates (1000~250 μm and 250~53 μm)accounted for 69.53% and 82.71% in Gaocheng and Xingtang area, respectively. Organic carbon content in <20 μm aggregates was 12.78 in Gaocheng City and 20.02 g/kg and in Xingtang County, respectively, which can be considered as a stability index for cinnamon soil carbon sequestration in studied area. Fourier transform infrared spectroscopy showed that aromatic carbon (macroaggregates:57.35%;microaggregates:67.69%) and carbohydrate carbon (macroaggregates:29.43%;microaggregates:25.2%) were the major organic carbon in studied area. Organic carbon in macroaggregates was mainly composed of labile carbon such as aliphatic carbon and carbohydrate carbon,et al. The stable aromatic carbon tend to be protected in microaggregates (Gaocheng City:57.89%;Xingtang County:77.51%).