The effects of the mixture ratios of swine manure and food wastes when vermicomposed on earthworm(Eisenia foefida) growth, the production amounts and the chemical properties of casts for plant growth media were evaluated to optimal mixture ratio. Earthworms were grown in swine manure, substituted with 0%, 20%, 40%, 60%, 50% and 100% food wastes. All of earthworm grown in swine manure substituted with 60%, 80%, and 100% food wastes died, therefore the process of swine manure substituted with 60%, 80%, and 100% food wastes by vermicomposting were impossible in this experiment. Worm cast produced from swine manure substituted with 0%, 20% and 40% food wastes after vermicomposting sufficiently contained required quantities of available phosphorus, exchangeable potassium, exchangeable magnesium, and cation exchange capacity. The survival rates of earthworm in swine manure substituted with 0% and 40% food wastes was significantly higher than those in swine manure substituted with 20%, 40% food wastes. Casts weight and proportion of casts weight in 100% swine manure were significantly higher than those in swine manure substituted with 20% food wastes, but was no significant difference between those in swine manure substituted with 40% food wastes. Therefore 100% swine manure was estimated to be superior than the others treatments. However an adequate mixture ratio of food wastes for processing mixture of swine manure by vermicomposting was estimated to be 40%. Because there was no significant difference in mean flesh weight, increasing rate, casts weight, proportion of casts weight, and reduction rate of volatile solids among 3 treatments and survival rate and conversion efficiency(CE) in swine manure with substituted 40% food wastes were significantly higher than the other treatments.