The electrode-organic interfacial properties play a critical role in determining the performance of OLEDs.A number of anode modification techniques and device architectures are developed for enhancing OLED performance.Accomplishments in developing techniques for engineering interfacial properties to ensure electronhole current balance in OLEDs will be discussed.In practical applications,the visual contrast is more important than the brightness of image.As such,improving the visual contrast in OLED displays is another important issue to address with a significant technological implication.This talk will also discuss the progress in developing color tuning with graded anode thickness and gradient refractive index anode for enhancing the visual contrast of OLED displays.