Electrical and optical characteristics of the GaN-based light-emitting diode (LED) with the improved multi-quantum well (MQW)structure have been studied for light source in bio-sensing systems. Novel GaN/In0.1GaN/In0.2GaN/In0.1GaN/GaN and Al0.1GaN/GaN/In0.2GaN/GaN/Al0.1GaN (MQW) structures were suggested, and their radiative recombination rate, light output power, electroluminescence,and external quantum efficiency were compared with those of the conventional GaN/In0.2GaN/GaN MQW structureusing device simulation. The LED with the GaN/In0.1GaN/In0.2GaN/In0.1GaN/GaN MQW structure showed an excellent recombination rate of 5.57 ×1028 cm-3·s-1 that was more than one order improvement over that of the conventional LED. In addition, the efficiencydroop was relieved by the suggested stepped MQW structure.