In the present study,pigment isolated from Tibetan purple hulless barley was subjected to a primary study to characterize their basic physicochemical properties,stability and antioxidation.The results showed that the pigment was anthocyanin colorant which exhibited red,green,yellow-brown or bluish violet color depending on the solution and its pH value;the pigment was more stable at lower pH in the dark than at higher pH under light;metal ions including K +,Na +,Ca2 +,Mg2 +,Zn2 +,Al3 +,especially those highly charged ions had significant hyperchromic and protective effect on storage stability of the pigment;the binding modes or affinities between the metal ions and an-thocyanin pigments could be different according to HPLC analysis;the great elimination efect on the hydroxy radical with IC50 values of 9.7 mg/L indicated hulless barley pigment was an excellent natural antioxidant.