The Mollisol is an important arable soil. A quickly decrease of organic matter in the Mollisol had limited the agricultural production and crop yields. The relationship between the input amount of organic manure application and the contents of carbon and nitrogen in soil particulate organic matter was investigated using soil samples from a long-term field experiment in National observation station of Hailun agro-ecology system to restore the soil fertility of a Mollisol. Soil samples from 0-20 cm layer were collected in four treatments including: chemical fertilizer (OM0), low amount organic manure (OM1), medium amount organic manure (OM2), high amount organic manure (OM3) set up in 2001. Physical fraction of organic carbon was used to test soil organic carbon, nitrogen and the contents of different fractions. Soil organic carbon and nitrogen were significantly increased by long-term organic manure application (P<0.05). Soil organic carbon and nitrogen contents were increased by 0.186 kg and 0.02 kg when organic manure application was increased by 1 t, respectively, indicating that increased organic manure was an effective practice for increasing organic carbon and nitrogen of the soil. Organic manure application enhanced coarse particulate and fine particulate fractions with the order of OM3>OM2>OM1>OM0, while mineral particulate fraction was decreased. Organic carbon and nitrogen contents in coarse particulate and fine particulate fractions were increased with the increasing organic manure application, suggesting that organic carbon and nitrogen in coarse particulate and fine particulate fractions were main storing form of soil organic carbon and nitrogen for the Mollisol. The impact of chemical fertilizer and organic manure application on soil organic carbon and nitrogen was attributed to the formation and transformation of active particulate fraction. The application of organic manure significantly reduced C/N ratios in particulate and mineral fractions with the order of OM1>OM2>OM3 compared with OM0. The combination of chemical fertilizer and organic manure significantly increased soil organic carbon and nitrogen in bulk soil, coarse particulate and fine particulate fractions compared with OM1. High amount of organic manure with chemical fertilizer application was the most effective practice to improve soil fertility and quality.