Objective: To understand the level of nutritional literacy and its influencing factors among schoolage children in grades 4-9 in Guizhou Province, and to explore the relationship between nutritional literacy and physical health, so as to provide reference for improving nutritional literacy and physical health of schoolage children. Methods: Using multistage stratified cluster sampling method, 1 155 schoolage children in grades 4-6 in elementary school and grades 7-9 in secondary schools in three prefectural and municipal cities of Guizhou Province (Zunyi, Tongren, and Bijie) were sampled from February to July 2023, and were surveyed for nutritional literacy by using the "Food and Nutritional Literacy Questionnaire for Chinese Schoolage Children", and their physical health data (data on body measurement indicators, such as height, weight, lung capacity, and vertical jump) were obtained from the physical health surveillance platform. Pearson correlation analysis and binary Logistic regression modeling were used to explore the association between nutritional literacy and physical health. Results: The nutritional literacy score of the study population was (63.50±8.63), and the scores of each level of nutritional literacy in descending order were interactivity (66.09±13.99), functionality (63.84±8.80), and criticism (61.15±14.65); and the scores of cognitive domain of nutritional literacy, and skill domain were (64.71±10.77) (62.97±9.21); food selection, food preparation, and food intake dimension scores were (64.68±13.52) (56.39±12.17) (63.63±10.04), respectively. Differences in the total nutritional literacy scores of schoolaged children who were only children or not, by gender, ethnicity, grade level, primary caregiver, primary caregivers education, and family economic situation were statistically significant (t/F=2.88, -3.28, 5.02, 18.32, 4.67, 32.47, 32.53, P<0.05); the physical health pass rate was 85.8%, and the mean scores of the total physical health score, physical form, physical function, and physical fitness dimensions were (71.86±10.52) (93.29±12.06) (72.12±14.42) (67.26±13.13), respectively; after controlling for confounders, the nutritional literacy scores were positively correlated with physical health (OR=1.03, 95%CI=1.01-1.05, P<0.05). Conclusion Nutritional literacy scores of schoolage children in grades 4-9 in Guizhou Province are low, and there is a positive correlation between nutritional literacy and physical health in this school age children.