A method for manufacturing composite for bone grafting, comprising: a. pulverizing a tooth to generate tooth powder, and washing and degreasing the tooth powder; b. completely demineralizing the tooth powder to obtain dentin collagen as a collagen mass of 100% organic material derived from a tooth that is obtained when the tooth powder is completely demineralized; c. preparing a growth factor containing a bone growth-inducing component; and d. synthesizing a composite by mixing the obtained dentin collagen with the growth factor, wherein in the step for washing and degreasing of the tooth powder, the tooth powder is washed with distilled water for 40 minutes to remove contaminants and residual soft tissues, followed by degreasing the washed tooth powder in ethanol for 2 to 12 hour, wherein the step for completely demineralizing the tooth powder includes completely demineralizing degreased tooth powder in a hydrochloric acid solution in the range of 20 times volume of 0.2 to 0.7 N for 6 to 12 hours, wherein the step for synthesizing the composite includes: a. mixing the obtained dentin collagen and growth factor; and b. agitating the mixture of the obtained dentin collagen and growth factor at 30 to 80 rpm for 3 to 5 minutes, and the growth factor in a mixed state are maintained at pH 6.5 to 8, and wherein the growth factor is selected from a group consisting of one or more of those, such as recombinant human bone morphogenetic protein (rhBMP-2), double complex of amino acids to construct BMP, fibroblast growth factor, growth differentiation factor, transforming growth factor, platelet-derived growth factor, insulin-like growth factor, epithelial growth factor, keratinocyte growth factor 2, morphogenetic protein 52, recombinant proteins thereof, and mixtures thereof. a. pulverizing a tooth to generate tooth powder, and washing and degreasing the tooth powder; b. completely demineralizing the tooth powder to obtain dentin collagen as a collagen mass of 100% organic material derived from a tooth that is obtained when the tooth powder is completely demineralized; c. preparing a growth factor containing a bone growth-inducing component; and d. synthesizing a composite by mixing the obtained dentin collagen with the growth factor, wherein in the step for washing and degreasing of the tooth powder, the tooth powder is washed with distilled water for 40 minutes to remove contaminants and residual soft tissues, followed by degreasing the washed tooth powder in ethanol for 2 to 12 hour, wherein the step for completely demineralizing the tooth powder includes completely demineralizing degreased tooth powder in a hydrochloric acid solution in the range of 20 times volume of 0.2 to 0.7 N for 6 to 12 hours, wherein the step for synthesizing the composite includes: a. mixing the obtained dentin collagen and growth factor; and b. agitating the mixture of the obtained dentin collagen and growth factor at 30 to 80 rpm for 3 to 5 minutes, and the growth factor in a mixed state are maintained at pH 6.5 to 8, and a. mixing the obtained dentin collagen and growth factor; and b. agitating the mixture of the obtained dentin collagen and growth factor at 30 to 80 rpm for 3 to 5 minutes, and the growth factor in a mixed state are maintained at pH 6.5 to 8, and wherein the growth factor is selected from a group consisting of one or more of those, such as recombinant human bone morphogenetic protein (rhBMP-2), double complex of amino acids to construct BMP, fibroblast growth factor, growth differentiation factor, transforming growth factor, platelet-derived growth factor, insulin-like growth factor, epithelial growth factor, keratinocyte growth factor 2, morphogenetic protein 52, recombinant proteins thereof, and mixtures thereof.