Maltose corn syrup is made by liquefaction and saccharification. In tradition, the materials are stewed till concentrated into syrup with the saccharifying agent malt after being boiled. The product, called malt syrup, contains 35-45% maltose, saccharin, a little maltotriose and glucose. In industry, enzymatic saccharification is a technology which grinds starch and heats it till gelatinized, then saccharifies it with maltose after liquefaction with α— amylase. The maltose syrup transforms into starch syrup after decoloration and Ion Exchang. Maltose content is not strictly regulated, usual maltose contains 40-50%, medium 50-60%, high≥70%。