To what extent do expert opinions affect public opinion in policy making? While most existing studies were conducted in democracies, experts' influence under authoritarian settings is still understudied. This paper examines how expert opinion and vocational affiliation influence public attitudes toward genetically modified (GM) food in China. Through a survey experiment with over 1600 respondents, we find that experts' endorsement can increase policy support for GM food but that their opposition exerts no influence. Different vocational affiliations do not generate significantly different effects, although endorsement from foreign experts has larger effects than endorsement from domestic counterparts, who have closer connections with the Chinese government. We finally discuss the policy implications of expert involvement in policy making and promoting GM food in China based on the above findings.