Abstract: In the present study, the contents of main components（starch, sugar and amino acid）, amylase activity and aroma components of sweet potatoes involving Maillard reaction before and after 15, 30, 45, 60, 75, 90, 105 and 120 minutes baking were determined, and the dynamic changes of each indicator during baking process were analyzed, aiming to further elucidate the mechanism of aroma formation of roasted sweet potatoes. The results showed that the total contents of starch and amino acids in sweet potatoes were decreased first and then stabilized with the increase of baking time compared with untreated group, and the loss of serine and aspartic acid accounted for 84.56% of the total amino acids loss; whereas the contents of soluble total sugar, reducing sugar and maltose were ascended first and then descended with the prolonged baking time, and the contents of glucose,fructose and sucrose showed almost constant values. Besides, the amylase presented gradually decreased activities with the prolongation of baking time, which would be completely inactivated at 45 minutes; moreover, the total contents of aroma components were improved first and then reduced with the increase of baking time.