A calcium phosphate composition comprising calcium phosphate particles (A) and a sulfonic acid salt (B), wherein the calcium phosphate composition contains 0.5 to 20 parts by weight of the sulfonic acid salt (B) based on 100 parts by weight of the calcium phosphate particles (A). This provides a calcium phosphate composition that has a time between the addition of a liquid agent to the calcium phosphate composition and the completion of setting in the use at a clinical site and the like, i.e., a setting time which is within an appropriate range and that is high in mechanical strength and good in marginal sealing ability.
