Different concentrations of malondialdehyde were used to oxidize rice bran protein， and then the rice bran protein was heat-treated in a condition of 95 ℃ water bath to investigate the effect of heat treatment on in vitro pepsin digestibility of rice bran protein and antioxidant activity of rice bran protein hydrolysates. The results showed that as concentration of malondialdehyde increased， the content of carbonyl and disulfide bonds of rice bran protein increased， and the content of free sulfhydryl decreased， which confirmed that oxidative modification by malondialdehyde resulted in oxidation of rice bran protein. As malondialdehyde concentration increased， pepsin digestibility， initial digestion rate of rice bran protein， and content of peptides with molecular weight distribution of 500-1 500 u in the pepsin digestion products gradually deceased. In addition， free radical scavenging abilities on ABTS+·， DPPH·， ·OH， O2-·， metal chelating ability and reducing power of rice bran protein in vitro pepsin hydrolysates gradually deceased. Heat treatment could increase pepsin digestibility， initial digestion rate of rice bran protein as well as active peptide content and antioxidant activity of rice bran protein in vitro pepsin hydrolysates. The results indicated that oxidative modification by malondialdehyde lead to decease of rice bran protein digestibility and antioxidant activity of rice bran protein in vitro pepsin hydrolysates， and the moderate heat treatment could result in increase of rice bran protein digestibility and antioxidant activity of rice bran protein in vitro pepsin hydrolysates.