Recombinant human calcitonin (hCT) can be expressed by Pichia pastoris as a precursor peptide. Full length of synthetic hCT gene was inserted into pPICZαA vector under control of AOX1 promoter, downstream of the secretion-α-factor and electroporated into P.pastoris KM71H (mut s ) strain. Molecular analysis, including polymerase chain reaction (PCR), sequencing, restriction enzyme analysis and surviving of P. pastoris to increasing concentration of zeocin antibiotic showed that human calcitonin gene was successfully integrated into the P. pastoris genome. The expected peptid which had an apparent molecular mass of 5.5 kDa, was detected by TricineSDS-PAGE analysis and confirmed Western blot.