We had investigated the potential of non‐polar a‐plane InGaN/GaN multiple quantum well (MQW) for high indium content blue/green emission. By comparisons of a‐plane and c‐plane MQW with different indium compositions, we concluded that without piezoelectric field, high indium content non‐polar a‐plane InGaN/GaN MQW is suitable for green light emitting diode (LED). Furthermore, similar to c‐plane GaN InGaN/GaN MQW, the localized state might enhance the performance of a‐plane MQW while the indium composition about 24% although the threading dislocation density (TDD) is quite high. On the other hand, the indium phase separation might also occur on a ‐plane InGaN/GaN MQW while the indium composition about 30% so that the photoluminescence intensity of the sample 810 °C low down and spectrum bandwidth broaden. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)