Objective: To investigate the current situation of sitting time and health literacy among high school students in China, in order to provide a basis for improving their physical and mental health levels. Methods: A stratified random cluster sampling method was used to investigate the length of sitting time and health literacy of first and second grade high school students from 31 provinces, cities, and autonomous regions in China(data did not include that of Hong Kong and Macao Special Administrative Region, and Taiwan Province of China). The Kruskal-Wallis H method, independent sample Mann-Whitney U test, and regression model were used to analyze the influencing factors of sitting time and total health literacy score. Results: (1) The total score of health literacy was statistically significant (P < 0.01) in different regions, urban and rural distribution, annual family income, parents' educational background, age, and gender. (2) The length of sitting was statistically significant (P < 0.01) among multiple groups in different regions, family annual income, parental education, and gender. However, there was no statistically significant difference between groups of different ages and urban-rural distribution (P>0.05). (3) The analysis of multiple linear regression model showed that the total score of health literacy was positively correlated with the family' s annual income and the mother' s education, and negatively correlated with the father' s education and the length of sitting. Standardized regression coefficient β comparison: Father' s education (-0.32) > family annual income (0.15) > mother' s education (0.09) > average daily sitting time (-0.02), with father' s education having the greatest impact, followed by family annual income. The length of sitting was positively related to the family' s annual income and the mother' s educational background, and negatively related to the total score of health literacy. Standardized regression coefficient β comparison: Annual family income (0.14) > education background of mother (0.13)> total score of health literacy (-0.02), with the impact of annual family income the largest, followed by education background of mother. Conclusion: China' s first and second grade high school students generally spend a long time sitting every day, and the level of health literacy is generally low. The level of health literacy and sitting time are negatively correlated with each other, and are most influenced by the educational background of high school students' parents and their family economic levels.