Abstract Precipitation-dissolution equilibrium occurs in heterogeneous systems. This phenomenon is widely existed in medicine and life science, such as the formation of bones, dental caries, renal calculi and urinary calculi and so on. In order to enable medical students to better understand and master the knowledge of precipitation-dissolution, the author started with medical cases through the "problem-oriented" teaching mode, and ended with the causes and preventive measures of diseases. So the way of ending corresponded to that of starting. This teaching form shows the interaction between a teacher and students. It brings about very effective teaching, helps students learn with problems, and stimulates students' interests in learning and their subjective initiative. It also helps develop students' abilities to explore and solve a problem. Thus, students have chances to become men who have an ability of exploration with independent and innovative thinking. What we discussed here can be applied to other chapters of Basic Chemistry in Medication, which is of great guiding significance.