Objective:To study the effects of indoor illumination on learning efficiency in university classrooms, and to provide reference for the rational arrangement of classroom light setting in universities. Methods:The experiment was carried out in real university classrooms. Three illumination levels were employed at (2 167.77±46.33)lx, (331.17±6.51)lx and (64.22±3.38)lx. 10 university students were recruited to engage in the test on subjective sensation and learning efficiency in the whole course of experiment. Results:The three levels of illumination had significant effects on the light environment evaluation, negative emotion, general situation of emotional state and learning enthusiasm of the students (P<0.05). There was no significant difference in Sick Building Syndrome (SBS), positive emotion and self-assessment on learning efficiency among the three levels of illumination (P>0.05). Illumination had significant effects on learning efficiency in the cognitive tests (P<0.05) except reading comprehension test. It was found the most disruptive to accuracy, speed and performance in almost all tests were lowest in low-illumination environment. Conclusion:The illumination level of university classrooms affects students' subjective feelings, emotions, comfort and learning efficiency. Therefore, it is necessary to better design the light setting environment in classroom with adjusting and controlling indoor illumination to create more comfortable and efficient learning zones for the university students.