Abstract: As one of the abundant renewable natural resource which is inferior to cellulose, starch is readily available and inexpensive. It also can be degraded easily and turned into useful ramification by biochemical method. Every country attaches much importance to exploiture of starch resource for a long time. Especially many investigators and manufacturer have done works on natural starch denaturalization which is becoming the hot spot through physical, chemical and biological methods. In this paper, the process in studies on modified starch based on biological methods by carbohydrase is summarized. The kinds of carbohydrase, action patterns and preparations of the bio-modified starches (resistant starch, microporous starch, branched cyclodextrin, slowly digestible starch, starch film, starch esterification etc.) are introduced. The long-term potential development of bio-modified starch is prospected.

Key words: bio-modified, carbohydrase, preparation, kind, action pattern