A stackable modular personal computer structure comprises a lowermost frameworks, a plurality of intermediate frameworks, an uppermost framework and an upper cover; the frameworks and the upper cover stacked with each other in a sequence; all the frameworks have the first internal engaging structure inside the tops thereof respectively, the intermediate frameworks, the uppermost framework and the upper cover each have the second internal engaging structure inside the bottoms thereof respectively; the bottoms of each of the intermediate and the uppermost frameworks has a hole especially for electric wires to pass through to enable the modular personal computer so that a consistent outlook for the computer structure can be obtained.