A server system utilizing a backplane structure comprises first and second hard disk modules; a first backplane comprising a first wiring board comprising air vents and passive components and a second wiring board connected to a bottom portion of the first wiring board at a first angle and comprising first active components; and a second backplane comprising a third wiring board comprising second air vents and second passive components and a fourth wiring board connected to a bottom portion of the third wiring board at a second angle and comprising second active components thereon; wherein the first and second backplanes are disposed between the first and second hard disk modules; the first wiring board is directly corresponding to the first hard disk module; the third wiring board is directly corresponding to the second hard disk module; the first backplane is higher than the second backplane.