Room-temperature deformation behavior in the localized regions of W-80vol%Cu composite was investigated in this study. Plastic strain of about 10 % was added to the specimen at room temperature using a three-point bend testing machine. Then deformation behavior in a localized region was investigated using a high-magnification SEM photograph before and after deformation. Results are summarized as follow. (1) In a localized region near a large pore, heterogeneous deformation had occurred as expected. (2) In a region apart from a pore, mostly homogeneous deformation occurred but occasionally heterogeneous deformation occurred.