Abstract: In the present paper, we report the preparation of a series of Fentanyl derivatives which are N-1-(β-arylalkyl)-4-piperidyl-N-propionyl aniline, N-1-(β-phenylet-hyl)-4-piperidyl-N-amidoaniline, N-1(-β-phenylethyl)-4-piperidyl-E-propionylary-lamine, N-1-(β-arylethyl)-4-tropyl-N-propionyl aniline and N-1-(β-arylethyl)-4-pyrrolidinyl-N-propionyl aniline. A total of 22 compounds were synthesized.Pharmacological results showed that most of the compounds in these series possessed morphine-like effects in laboratory animals with potencies levels 2～150 times those of morphine.