Abstract: In order to study different baking process on the influence of tobacco leaf cell ultrastructure, the leaves cell ultrastructure of flue-cured tobacco ‘KRK26’ were studied by microscopic observation with the three curing techniques were made by different yellowing, color-fixing temperature and humility conditions which were lower temperature and lower humidity, middle temperature and middle humidity, middle temperature and higher humidity. The result showed that: (1) With the three kinds of curing techniques, chloroplast form change, structure the disintegration of the speed was different, it was appear late but fast in lower temperature and lower humidity condition; it was appear early and slowly in middle temperature and middle humidity condition; it was appear early and slowly in middle temperature and higher humidity condition. (2) With the three kinds of curing techniques, the form of the mitochondria, ridge quantity and membrane structure changed the disintegration of speed for performance lower temperature and lower humidity less than middle temperature and higher humidity less than middle temperature and middle humidity.