Natural bone is a kind of organic-inorganic hybrid composed of collagen and apatite crystals with a structure that provides specific mechanical properties such as high fracture toughness and flexibility. Materials exhibiting both high flexibility and bioactivity similar to natural bone are required for novel bone-repairing materials in medical fields. We expect that we can design such materials by mimicking the bone structure. Biomimetic process has been paid much attention where bone-like apatite is deposited on organic polymers in simulated body fluid (SBF). In this study, we investigated influence of cross-linking agents on apatite-forming ability of pectin gels. Pectin is a polysaccharide abundant in carboxyl group. Pectin gels were prepared by cross-linking of pectin aqueous solutions with calcium ions or divinylsulfone (DVS). Apatite-forming ability of the gels was examined in SBF. The citrus-derived pectin showed tendency to form the largest amount of the apatite independent on a kind of cross-linking agents in SBF.