The study is a comparative study of differences between Korea and France regarding biology teachers' conception about genetic determinism of social behaviors in human. To investigate differences in two countries, the questionnaire, built and validated by the Biohead-Citizen project, and including six questions related to genetic deter-minism of social behaviors in human, was completed by 308 teachers in Korea and 732 teachers in France. The results show that Korean teachers' conception about genetic deter-minism is four times higher than teachers in France. Genetic determinism conceived by biology teachers in Korea seems to be mainly influenced by their personal and socio-cultural contexts, while biology teachers in France are influenced by both their special knowledge in biology and socio-cultural contexts. Biology teachers in Korea are called for reducing their conceptions about genetic determinism through teacher education programs and understanding advanced knowledge in molecular genetics. Further genetic related contents in secondary school biology curriculum in Korea are also needed to update and strengthen recent knowledge in molecular genetics.