To obtain a new human calcitonin derivative, having a variation of an amino acid residue at a specific site of a natural type calcitonin, having higher activities and less adverse effects than those of the natural type, strong lowering actions on calcium in blood and useful for treatment, etc., of osteoporosis, pain, etc.

This new human calcitonin derivative (salt) is a derivative in which at least one position of the 17-, 22- and 24-positions and optionally an amino acid residue at the 15-position in the natural type calcitonin having an amino acid sequence represented by the formula are substituted by other amino acid residues; Asp at the 15-position is substituted by Glu; Asn at the 17-position is substituted by His; Phe at the 22-position is substituted by Tyr and Gln at the 24-position is substituted by Arg. The calcitonin derivative (salt) has higher activities and less adverse effects than those of the natural type and is useful as a therapeutic agent, etc., for osteoporosis, pain, etc. The derivative is obtained by synthesizing the amino acid sequence in which the 15-, 17-, 22- and 24-positions, etc., of the natural type calcitonin by using a peptide solid- phase synthetic method, etc., utilizing a polymer resin.