A beta -glucan-containing fat and oil composition of the invention which contains beta -glucan of microorganism origin or basidiomycete origin. The beta -glucan -containing fat and oil composition of the invention has beta -glucan uniformly dispersed in a food without worsening the texture, taste etc. of the food. The novel microorganism of the invention can efficiently produce beta -glucan which has a high activity and favorable qualities as beta -glucan of microorganism origin as described above from less expensive saccharides such as sucrose at a high production speed.
