① nifedipine as anti-angina drug. For hypertension, angina and other diseases. ② these new agents using advanced control drug release rate of the preparation process, the slow release of drug in the body, significantly improved its pharmacokinetic characteristics, it is to improve patient medication compliance. ③ This paper investigated by several commercially available factor method similar to nifedipine in vitro drug release similarity comparison of the release curve to understand the degradation of these drugs in the release process of law, and their in vitro release similarity, for the assessment and control of drug quality and rational use of clinical reference.