The molecular weight and molecular weight distribution of polymers is one of the important parameters affecting the properties of polymers

so it is an important knowledge point in Polymer Physics. Analogy teaching method which takes this knowledge point as the example is used in the teaching experience. Firstly

the students are guided to comprehensively grasp the characterization methods and principles of molecular weight and molecular weight distribution of polymers by the method of summarizing to "give one". Then three examples are carefully prepared from easy to difficult

which are resolved correctly by comparison

analogy

and association of the summarized knowledge points. Through the training

the analogical thinking and flexible using ability of students are trained

so the purpose of training is achieved. In order to further deepen students' understanding of knowledge points

students are required to adopt the "anti-three" mode in the homework. There are many types of highly quality questions proposed by students self-questioning and self-answering. It is shown from the students' homework that the teaching method proves a good effect.