Thermal processing can destroy harmful microorganisms in food， but also can change the flavor and texture of meat products and their nutritional and digestive properties. In addition， excessive thermal processing can lead to protein oxidation， effect the sensory quality of aquatic products and nutritional value. In order to reduce oxidation of proteins during thermal processing， natural polyphenols are used to improve the functional properties or nutritional value of proteins. The effects of different concentrations of epigallocatechin gallate (EGCG) and epigallocatechin (EGC) on sensory properties and protein oxidation of microwave-heated sea bass fillets were investigated. The results showed that EGCG and EGC can decrease significantly cooking loss， and the cooking loss rate was decreased by 47.98%-62.72% and 38.54%-58.63%， compared with the control. Hardness and chewiness， carbonyl， free amino and disulfide bond content of sea bass fillets were decreased， but moisture content and sulfhydryl group content were increased. EGCG and EGC significantly improved the breakage and aggregation of muscle fiber tissues in sea bass fillets； reduced the acidity in the fillets and did not increase their astringency. EGCG and EGC reduced the volatile odor of nitrogen oxide-type and contributed to the generation of sulfur-containing compounds-type odor in the sea bass fillets.