This paper studied the effects of foliar spraying of amino acids and chitosan on plastid pigment, enzymatic activity and aroma constituents of flue-cured tobacco leaves after topping. Results showed that: the contents of Chlorophyll and carotenoid, the activities of phenylalanine ammonia-lysae (PAL) and lipoxgenase (LOX) were higher than other treatments, chitosan treatment had no significant influence; the contents of aroma constituents of amino acids treatment were higher than those of chitosan treatment and CK, particularly there was a significant effect on phenylalanine and Maillard reaction product, increased by 20.9% and 23.1% respectively. The content of phenylalanine increased by 17.6% compared with CK. The proportion of the plastid pigment and relating enzyme changed under amino acids treatment, which were better than chitosan’s influence on aroma quality of flue-cured tobacco.