435 heroin addicts were treated for 10 days to evaluate the therapeutic effectiveness of abstinence capsule on heroin withdrawal symptoms and its main adverse actions. Lofexidine was applied in a control group of 48 addicts. The single blind method and some determination methods used internationally were employed to evaluate the therapeutic effectiveness and adverse actions of the drugs. The results showed that the abstinence capsule has better therapeutic effectiveness, with less adverse actions, wider safety range, longer time of action and less cost than lofexidine.