The mature peptide domain of melanin concentration hormone1 (MCH1) from Cynoglossus semilaevis Günther was amplified with specific primers based on their cDNA sequences from NCBI. Then the matured peptide fragments were subcloned into the prokaryotic expression vector pET-32a to successfully construct MCH1/pET-32a recombinant plasmid. The obtained recombinant MCH1 protein expressed in form of inclusion bodies with molecular weight of 29.9 ku and maximally accounted for 50% of the whole bacterial protein post 6-hour induction with 0.2 mmol/L IPTG at 32℃. Western blotting analysis indicated that the obtained recombinant MCH1 protein had the antigenicity to His 6 antibody.The obtained target MCH1 protein was purified using Ni²⁺-NTA affinity chromatography method. The bioactivity of obtained target MCH1 protein was tested by the method of in vitro incubation of pituitary gland. The results showed that MCH1 recombinant protein can effectively stimulate or inhibit the secretion of pituitary MCH and MSH peptides. Wherein, the MCH peptide level increased with the MCH1 protein concentration and peaked at 100 nmol/L, however, it dramatically decreased at 1000nmol/L; the MSH peptide level showed a significant rise at 100nmol/L group, and peaked at 1000nmol/L of MCH1 protein. As for gene expression patterns, the MCH1 and MCH2 mRNAs levels showed similar variation trend, wherein MCH1 mRNA showed upregulated expression with the recombinant MCH1 protein increasing, and peaked at 10 nmol/L group, and MCH2 mRNA levels peaked at 100 nmol/L group. The pituitary PACAP and POMC-a mRNAs both exhibited down-regulated expression trends, and POMC-b, MCHR1, MCHR2, MITF mRNAs expression levels were not significantly affected by exogenous recombinant MCH1. In summary, the recombinant MCH1 protein could adjust the physiological functions of pituitary hormone secretion and gene expression. The present results could provide basic knowledge and technical support for development of high-efficient and specific additives which could be applied to aquaculture of C. semilaevis.