The invention discloses an organic electroluminescent device comprising a pixel element. The pixel element comprises a substrate comprising a control area and a sensitive area, a switch device and a driving device overlying the control area, a photo diode serving as a photo sensor overlying the sensitive area, an OLED element disposed in the sensitive area and illuminating to the photo sensor, and a capacitor coupled to the photo sensor and the driving device. Specifically, a photo current corresponding to a brightness of the OLED element is generated by the photo diode responsive to the OLED element illuminating the photo diode such that a voltage of the capacitor is adjusted by the photo current to control the current passing through the driving device, thus changing the illumination of the OLED element. A method for fabricating the OLED is also provided.