A pixel structure for a display device is provided. The pixel structure utilizes light entering from the ambient environment of the display as a light source. The pixel structure comprises a first substrate, a light obstructing layer, an active element and an adjustable light shielding layer. The light obstructing layer is disposed on the first substrate and has a transparent area and an opaque area. The active element is disposed on the opaque area of the light obstructing layer and has a first state and a second state. The adjustable light shielding layer is disposed on the light obstructing layer and the active element. When the active element is in the first state, the adjustable light shielding layer is adapted to cover the transparent area to shield the light from emitting out from the first substrate. When the active element is in the second state, the adjustable light shielding layer is driven to uncover the transparent area so that the light is adapted to emit out from the transparent area and the first substrate.