The study included a set of five treatments:winter fallow-double cropping rice; milk vetch-double cropping rice; rape-double cropping rice; garlic-double cropping rice; and potato, milk vetch, and rape rotation-double cropping rice. The effects of multiple winter-cropping on the early-and late-rice yields, soil organic carbon, active organic carbon, and carbon library management index in double cropping rice field were studied for a period of three years (2013-2015). The early-rice yields of winter-crop treatments were higher than that of the control treatment. The late-rice yields of the winter treatments were also higher than that of the control; however, the late-rice yield of winter rape was lower than that of the control. The total organic carbon, active organic carbon, soluble organic carbon, microbial biomass carbon content, and carbon library index of the winter treatment were extensively improved. In addition to the winter crop rotation, the soil-carbon library management indices of the other winter treatments were significantly improved. A significant correlation was observed between the total organic carbon and active organic carbon, microbial biomass of soil, total organic carbon with the soluble organic carbon, and the carbon library management index. The carbon storage activity and carbon-storage activity index were also improved, but the effects were not significant.