Abstract: With reverse transcription-polymerase chain reaction（RT-PCR）,expression of endothelin A receptor （ETA-R ） mRNA in rats has been detected. It has been found that ETA-R mRNA not only exsisted in vascular smooth cell and endothelial cell ) but also distributed extensively in the brain, heart, kidneys, lungs and liver. In addition, this is the first report that ETA-R mRNA levels are significantly increased in the brain, heart and kidneys in spontaneously hypertensive rats. These data show that the high expression of ETA-R gene could be an important pathogenic factor for hypertension.