Abstract: With the conditions of commercial microwave processing, the relationship between microwave intensity and the denaturation of sarcoplasmic protein and myofibrillar protein in chicken breast was evaluated, which aimed at providing test parameters in the processing of chicken products with microwave.The changes of sarcoplasmic protein and myofibrillar protein were analysises using the biuret method and SDS-PAGE, with different heating fire:low fire, medium fire, high fire, and heating time:30, 60, 90, 120s.The results suggested that:with the increase of heating fire and time, the denaturation of the sarcoplasmic protein in chicken breast increased significantly, the extract concentration of myofibrillar protein first increased and then decreased with the low and medium fire, under the conditions of high fire the content reduced;The hermal stability of myofibrillar protein was higher than sarcoplasmic protein.From 30ku to 40ku, the thermal stability of protein was higher.The protiens had fully denatured precipitation until high-fire heating with 90s.