The Chinese herbs have been used for thousands years, their effects were certified in clinic. The compatibility of Chinese medicine prescriptions is the basis principle in clinical application. In order to enhance efficacy and reduce toxicity, reasonable compatibility of the Chinese herbs is the main method for the safety and effective use. However, it is not clear about its mechanism. So it is necessary to study their mechanisms by using the modern pharmacological technology. At present, there are some studies on the mechanisms of the compatibility relating with toxicity or adverse effect attenuation, for instance, reducing the dose of toxic Chinese herbs, changing their pharmacokinetic parameter and resisting the damage to human body system. In this paper, we planed to review the attenuation mechanism of the prescription compatibility from relevant studies.