Abstract: The degummed silk fibers were treated with disodium hydrogen phosphate and calcium nitrate solutions respectively by immersion method for mineralization so that the calcium phosphate could deposit on silk fibers. The sediment state of calcium phosphate on silk fibers was investigated by SEM, and the structure of the sediment was analyzed by XRD. The results showed that the sediments on silk fibers were mainly scale-like and needle-like hydroxyapatite crystals. Tensile strength testing of the mineralized fibers indicated that they became harder and their breaking extension and strength decreased, but the changes were not distinct. The calcium phosphate has good affinity to silk fibers, can deposit on them with little effect on their properties.