The alkylamino group in pharmaceutics of Methadone series was substituted with piperidine group or carbonyl group with sulfonyl group to prepare 6-piperidino-4, 4-diphenylhexan-3-one, 6-piperidino-4, 4-diphenylheptan-3-one, ethyl 1, 1-diphenyl-3-piperidinopropyl sulfone, and ethyl 1, 1-diphenyl-3-piperidinobutyl sulfone. Comparative examination of these compounds was made on toxicity, antitussive and analgesic action, antihistamine and antiacetylcholine action, effect on respiration and blood pressure of a rabbit, and effect on isolated heart of a toad and rabbit. The activity of these compounds was similar to that of morphine, and the compounds had extremely strong antitussive, analgesic, and respiration sedative activity. On the contrary, antihistamine and antiacetylcholine activity of these compounds were weak. The compounds of heptanone series had stronger activity than those of hexanone series, their antitussive and analgesic activity being comparable to that of heroine and almost three times stronger than that of morphine. The compounds of hexanone series were comparable to morphine. The toxicity of sulfohexanone and sulfoheptanone was weaker than those of hexanone and heptanone, while their analgesic and antitussive effect was much stronger.