An organic light emitting diode (OLED) display and thin film transistor (TFT) manufacturing method thereof are disclosed. According to the present invention, poly-silicon layers for forming active areas of non-driving TFT (e.g. peripheral circuit TFT and switch TFT) and driving TFT used in the OLED display are respectively made by using standard laser crystallization method and non-laser crystallization method or low energy laser crystallization method. Therefore, the peripheral circuit TFT has excellent electrical performance such as high carrier mobility, while the OLED-driving TFT has good stability so that the resultant display can operate with improved luminance uniformity.