Objective: To survey the Chinese ophthalmologists' understanding of clinical research types and provide evidence in clinical and scientific research knowledge. Methods: In this cross-sectional investigation,we designed and developed a survey about different types of clinical research in ophthalmology. Correct
answers were worth one point each, and incorrect answers were worth no points. The correct answers were summed to get the total score. The educational background, professional qualifications, ranked distribution of hospitals of the surveyed ophthalmologists, size of the city, and attributes of the hospitals were stratified. The total score differences were compared and analyzed by Kruskal-Wallis H rank sum test. Multivariate logistic regression analysis was used to compare the relationship between total score and associated factors.  Results :A total of 233 questionnaires were distributed, and 197 were completed. The effective return rate was 84.5%. The average age of the respondents was 38.8土8.6 years, including 99 males (50.2%) and 98 females
(49.8%). The doctors scored higher than undergraduates (F=2.50, P<O.OOI), and residents scored higher than deputy chief physicians (F=3.17, P<O.O01). Ophthamologists practicing in Beijing, Shanghai, and Guangzhou (BSG) and in provinces and prefectures scored higher than those practicing in the countryside
(P<0.05). Multivariate logistic regression was used to analyze the relationship between the total score and other factors. For the total score, there were significant differences between BSG [OR=7.52 (2.27-24.96),P<0.001], provinces [OR=3.48 (1.21-10.02), P=0.02], and prefectures [OR=3.18 (1.19-8.48), P=0.02] and
the countryside. The other factors were not statistically significant. Conclusions: Highly educated students,residents, and doctors in big cities have higher perceptions of the types of clinical research. This suggests that the training of ophthalmologists should be strengthened and should start with medical students.