This invention illustrates a compact casing structure, integrally made by press-fitting at least one metallic material and adapted to be connected with a preset electronic device. The casing structure has a base portion which has a first stress region and a plurality of second stress regions. The plurality of circle shape second stress regions are arranged in intervals within the first stress region. The larger stress first stress region combining with the lesser stress and toughness second stress region can improve the strength of whole casing structure relatively, and the thickness of the casing structure can be made lighter to thinner, same and the usage amount of the material required in the casing structure can be reduced, and the cost of the casing structure can be decreased.