Abstract: Objective: To understand the current situation of permanent caries among some middle school students in Shaoxing city and analyze its influencing factors, and to explore preventive measures for permanent tooth caries, so as to improve the oral health care level of middle school students. Methods: We selected 1 526 middle school students aged 12 to 20 who underwent oral examinations in the Shaoxing Branch of Hangzhou Stomatological Hospital from June to August 2021 to conduct a questionnaire survey, and used logistic regression to analyze the influencing factors related to the prevalence of permanent tooth caries among middle school students. Results: Among the surveyed subjects, 460 permanent dental caries were affected, and the prevalence of dental caries was 30.46%. Through multivariate logistic regression analysis, we found that daily consumption of sweets (≥1 time) (OR=1.955, 95% CI: 1.494~2.559), eating often or before going to bed every night (OR=2.311, 95% CI: 1.770~3.019), the ability to use toothpicks and floss or water flossing habits (OR=2.441, 95% CI: 1.739~3.426) and parents suffering from dental caries (OR=1.802, 95% CI: 1.281~2.535) were risk factors for middle school students suffering from permanent dental caries (P＜0.05). We also found that daily fresh fruit consumption (≥1 time) (OR=0.527, 95% CI: 0.414~0.672), tooth brushing time (≥3 min) (OR=0.500, 95% CI: 0.372~0.672), food post-gargle habit (OR=0.545, 95% CI: 0.360~0.824) and regular oral physical examination (OR=0.577, 95% CI: 0.419~0.795) were protective factors for permanent dental caries (P＜0.05). Conclusions: The prevalence of permanent tooth decay among some middle school students in Shaoxing city was high, and it was affected by many factors. It was necessary to carry out targeted health education to cultivate a reasonable diet structure and standardized tooth protection habits to promote the healthy development of adolescents′oral cavity.