The invention discloses a compound of formula (I) capable of restraining and blocking M2 ion channel activity or its pharmaceutical acceptable salts or stereo isomers. The compound or its pharmaceutical acceptable salts or stereo isomers can restrain and block wild-type and variant influenza and avian influenza M2 ion channel activity through a novel action mechanism, thereby having the pharmaceutical function for treating wild-type and variant influenza and avian influenza; and simultaneously they can also used for treating hepatitis B, hepatitis C and AIDS, so as to provide more drug choices for clinical treatment.