The invention provides a type of novel 1,2,3,4-tetrahydroisoquinoline derivatives with a structure of formula (I):wherein R1 represents propargyl or cyclopropylmethyl wherein R2 represents N-ethyl-N-methylamino, 1-Pyrrolidyl, 1-Piperidinyl, or 1-Morpholinyl. The invention provides further a process for preparing said derivatives and a pharmaceutical composition containing the same. Said derivatives can be used to modulate the proteolytic process of amyloid precursor proteins (APP), and provides further novel compounds useful for treating Alzheimers disease (AD).