Objective：To design and synthesize 1，2，3，4-tetrahydroisoquinolines and to determine its inhibition effect on monoamine oxidase（MAO）. Methods：1-aminomethyl-1，2，3，4-tetrahydroisoquinoline was synthesized from phenylethylamine via acylation，ami－nation with phthalimide potassium，bisehler-napieralski cyclization，hydrazinolysis and reduction reaction. Then the title compounds were synthesized.Results：Four compounds with tetrahydroisoquinoline moiety were synthesized and their structures were confirmed by infrared spectroscopy，nuclear magnetic resonance spectroscopy and mass spectrometry. Pharmacological test in vitro showed that all the five compounds had certain MAO inhibitory activity，and compound（5~7） displayed preferable selective inhibition on MAO-A. Conclusion：The obtained compounds（5~7） need further study.