Abstract: Weak light stress on chemical components and main volatile flavor components in flue-cured tobacco was studied under full natural light irradiation and shading(transmittances of 80%,50% and 20%,respectively).The results showed that:the contents of starch,reducing sugar,total soluble sugar decreased,and the contents of total nitrogen and potassium increased under shading;the content of total neutral volatile flavor components also increased,among them,the content of neophytadiene obviously increased with the decrease of light irradiation,while the proportion of degradation products of carotenoid and cembranes,aromatic amino acid metabolites,and Maillard reaction products reduced.