A pixel structure of active organic light emitting diode is disclosed, which comprises an organic light emitting diode, a data-line, a scan-line, a switch thin film transistor (TFT), a control TFT, and a capacitor. The switch TFT has a first lightly doping drain and the control TFT has a second lightly doping drain. The doped concentration of the second lightly doped drain region is higher than that of the first lightly doped drain region. The leakage current in the switch TFT is reduced and the kink effect in the control TFT is improved by the pixel structure of an active organic light emitting diode. Therefore, a better display performance is provided.