Abstract: Protein content determination is an important technique of biological experiments.There are multiple methods for protein content determination in plants,among which Coomassie brilliant blue staining is one of the most common methods.The Coomassie brilliant blue method was introduced to determine the principle of protein content,reagents,equipment and procedures.It highlights the details that should be noted during the experimental operation and shares the experience accumulated by the laboratory.Practice has shown that this experiment greatly improves the accuracy and stability of the determination of protein content,expands the students’ professional knowledge,and improves their experimental skills.