Drug metabolism studies, including in vivo and in vitro metabolism studies, are significant in the design of candidate compounds and screening of lead compounds at drug discovery/development stages. Compared with in vivo metabolism studies, in vitro metabolism studies have the advantages of rapidity, simplicity, without consumption of large amounts of samples and animals. Moreover, it is convenient for researchers to observe the selective interaction between compound and target. Therefore, in vitro metabolism studies are appropriate for high throughput screening of compounds which are lack of metabolism information and have been widely used during drug discovery stages. This article briefly introduced the application of in vitro drug metabolism studies based on the metabolic stability, reaction phenotyping and metabolic drug-drug interactions, aiming to raise valuable evaluation strategies for innovative drug discovery in China.