The effect of addition amount of oat flour on the gluten and dough properties of oat-wheat mixed flour was investigated. The qualities of oat-wheat mixed flour were improved by addition of transglutaminase and exogenous proteins (peanut protein and gluten) and the protein composition of resulted mixed flour was also analyzed. The results showed that with the increase of oat flour content, the wet-gluten, gluten index, sedimentation value and stability time of oat-wheat mixed flour were significantly decreased and the water absorption was enhanced. In case of the mixed flour containing 30% oat powder, as the addition amount of transglutaminase was 0.8% (w/w) or more both dough development time and stability time were significantly increased. When transglutaminase and peanut protein were added into mixed flour at the same time, the relative content of SDS insoluble glutenin and dough stability time were further increased.