Abstract: Objective To investigate the health literacy level and influencing factors of primary school teachers in Jiangsu Province. Methods A total of 3 518 primary school teachers from 6 cities of Jiangsu Province were selected by multi-stage stratified sampling and were investigated with health literacy questionnaire. Results A total of 3 518 questionnaires were distributed and 3 514 were valid, the effective rate was 99.89%. The health literacy level of primary school teachers in Jiangsu Province was 66.6%. The Exhaustive chi-squared automatic interaction detector classification tree model showed that the most important factor affecting the health literacy level of primary school teachers was age (χ²=83.634,P<0.001), teachers of 44 years old and less were higher than those above 44 years old. In addition, the health literacy level of teachers in town and rural areas was higher than urban areas in ≤ 44 age group (all P<0.05). In (44-49] age group, teachers who had higher education level would have higher health literacy level (χ²=8.660,P=0.020). In > 49 age group, female teachers' health literacy level was higher than male (χ²=8.439,P=0.011). Conclusions The health literacy level of primary school teachers in Jiangsu Province was high, but there was still much room for improvement. The main factor affecting the health literacy level was age, the other influencing factors of health literacy in different age groups were various and it required targeted attention.