Human islet amyloid polypeptide(hIAPP)is a protein of 37 amino acids,co-secreted with insulin by islet β –cell and able to balance the level of blood sugar,except for the misfolded or aggregated ones,which are considered responsible for type II diabetes.[1] Dopamine is an endogenous substance of human body released by neurons as a neurotransmitter and also an important chemical messenger in both immune and digest systems.[2] Experimental results shows that DA has the character of specific binding to hIAPP to inhibit its aggregation.