A 3D display apparatus and a pixel array structure thereof are disclosed. The pixel array structure has a plurality of pixel rows. Each pixel row has a plurality of sub-pixels. Each sub-pixel has a first minor section, a second minor section and a major section. The major section is disposed between the first minor section and the second minor section. The brightness of the first minor section and the second minor section is lower than that of the major section. The 3D display apparatus can maintain the same display quality at top and bottom view angles.