To explore the effect of online and offline blended teaching mode on the teaching effectiveness of the course "Molecular Mechanisms of Cellular Signal Transduction". The 2022 grade doctoral students (n= 697) who adopted both online-offline mixed teaching mode and online mode were selected as research objects. The 2021 grade doctoral students (n= 692) who adopted both offline and online teaching mode were selected as control objects. Students' final grades and questionnaire satisfaction were analyzed to evaluate the teaching effect by processing data statistically. The effect of online-offline mixed teaching in 2022 grade is better than that of offline teaching in 2021 grade. In the class that adopted blended teaching reform, about 90% of doctoral students satisfied with the teaching objectives, the applicability of the course content, and the addition of the latest research progress in the course content, and believed that the course was helpful to the cultivation of students' scientific research thinking and the development of their research projects. The mixed teaching mode can improve the teaching effect of this course. It promotes the students' in-depth understanding and application of theoretical knowledge. These have been recognized by students.