Objective To develop a specific RNase Protection Assay to measure black seabream growth hormone (GH) receptor mRNA. Methods GH receptor cDNA fragment of black seabream was subcloned in pGEM|T vector. Then a specific antisense GH receptor RNA probe with radioactivity was prepared to hybridize with sense GH receptor RNA and total RNA from tissues of black seabream respectively. After hybridized solutions were treated with RnaseA/RNAseT1, the protected double strand hybridized RNAs could be detected by Autoradiogram and radioactivity counting. Results A specific RNase Protection Assay to measure black seabream GH receptor mRNA was developed. GH receptor mRNA were detected in brain, liver, kidney, muscle, gonad, gut and gill of black seabream, with highest level in liver. The results of GH receptor mRNA distribution were accorded with our previous results by GH Radioreceptor Assay in black seabream. Conclusion We can study the molecular mechanism of endocrine regulation by the specific RNase Protection Assay in black seabream GH receptor.