A bearing device for a wheel, comprising: a hub wheel; a constant velocity universal joint; and a double-row roller bearing comprising: an outer member having an inner circumference in which double-row outer raceway surfaces (26, 27) are formed; an inner member including the hub wheel having an outer circumference in which one of inner raceway surfaces (28, 29) opposed to the double-row outer raceway surfaces (26, 27) is provided, and an inner race externally fitted onto the hub wheel and having an outer circumference in which another one of the inner raceway surfaces (28, 29) opposed to the double-row outer raceway surfaces (26, 27) is formed; and balls accommodated in double rows between both the raceway surfaces (26, 27, 28, 29) of the inner member and the outer member so as to freely roll, the hub wheel, the double-row roller bearing, and the constant velocity universal joint being unitized together, wherein a recess-projection fitting structure, in which the hub wheel and a shaft section of an outer joint member of the constant velocity universal joint are integrated with each other, is provided, the recess-projection fitting structure being configured such that projections, which are provided on one of an outer surface of the shaft section of the outer joint member and an inner surface of a hole of the hub wheel so as to extend in an axial direction, are press-fitted to another one of the outer surface and the inner surface along the axial direction, characterized in that recesses, which intimately fit on the projections, are formed in the another one of the outer surface and the inner surface by the projections, and that entire regions of fitting contact regions between the projections and the recesses are brought into intimate contact with each other, wherein fitting between the inner race and a small diameter step section in a range corresponding to an outer surface side of the recess-projection fitting structure is non-interference fitting, and the fitting between the inner race and the small diameter step section in another range is interference fitting, and wherein a material is extruded from the recesses formed by the projections, and an extruded portion being equivalent to a volume of the material of the recesses is formed, the extruded portion including the material extruded from the recesses to be formed, the material cut for forming the recesses, or the material extruded and cut. a hub wheel; a constant velocity universal joint; and a double-row roller bearing comprising: an outer member having an inner circumference in which double-row outer raceway surfaces (26, 27) are formed; an inner member including the hub wheel having an outer circumference in which one of inner raceway surfaces (28, 29) opposed to the double-row outer raceway surfaces (26, 27) is provided, and an inner race externally fitted onto the hub wheel and having an outer circumference in which another one of the inner raceway surfaces (28, 29) opposed to the double-row outer raceway surfaces (26, 27) is formed; and balls accommodated in double rows between both the raceway surfaces (26, 27, 28, 29) of the inner member and the outer member so as to freely roll, an outer member having an inner circumference in which double-row outer raceway surfaces (26, 27) are formed; an inner member including the hub wheel having an outer circumference in which one of inner raceway surfaces (28, 29) opposed to the double-row outer raceway surfaces (26, 27) is provided, and an inner race externally fitted onto the hub wheel and having an outer circumference in which another one of the inner raceway surfaces (28, 29) opposed to the double-row outer raceway surfaces (26, 27) is formed; and the hub wheel having an outer circumference in which one of inner raceway surfaces (28, 29) opposed to the double-row outer raceway surfaces (26, 27) is provided, and an inner race externally fitted onto the hub wheel and having an outer circumference in which another one of the inner raceway surfaces (28, 29) opposed to the double-row outer raceway surfaces (26, 27) is formed; and balls accommodated in double rows between both the raceway surfaces (26, 27, 28, 29) of the inner member and the outer member so as to freely roll, the hub wheel, the double-row roller bearing, and the constant velocity universal joint being unitized together, wherein a recess-projection fitting structure, in which the hub wheel and a shaft section of an outer joint member of the constant velocity universal joint are integrated with each other, is provided, the recess-projection fitting structure being configured such that projections, which are provided on one of an outer surface of the shaft section of the outer joint member and an inner surface of a hole of the hub wheel so as to extend in an axial direction, are press-fitted to another one of the outer surface and the inner surface along the axial direction, wherein fitting between the inner race and a small diameter step section in a range corresponding to an outer surface side of the recess-projection fitting structure is non-interference fitting, and the fitting between the inner race and the small diameter step section in another range is interference fitting, and wherein a material is extruded from the recesses formed by the projections, and an extruded portion being equivalent to a volume of the material of the recesses is formed, the extruded portion including the material extruded from the recesses to be formed, the material cut for forming the recesses, or the material extruded and cut.