Epigallocatechin gallate (EGCG) was successfully grafted onto the carboxyl group of carboxymethyl yeast (1,3/1,6)-β-D-glucan (CMG) by chemical coupling method of 1-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC)/4-dimethylaminopyridine (DMAP). The structure and thermal stability of carboxymethyl yeast (1,3/1,6)-β-D-glucan-EGCG (CMG-EGCG) were characterized by FTIR, UV-Vis spectra and TGA. The antioxidant activity of CMG-EGCG was evaluated. The EGCG content of CMG-EGCG measured by folin-Ciocalteu method was 28.90 mg/g. The results showed that compared with CMG, CMG-EGCG had better thermal stability and antioxidant activity. When mass concentration was 1.0×10-3 mg/L, CMG-EGCG showed 78.85% of inhibition of DPPH free radical, 93.00% of inhibition of ABTS free radical, and its reducing capacity was 1.15. Those results show that CMG-EGCG can be used in cosmetics raw materials and food industry.