Temperature and injection-current dependencies of radiant flux from blue and ultraviolet GaInN/GaN multiple quantum well (MQW) light-emitting diodes (LEDs) were investigated. Experimental results indicate that, compared to blue LEDs, the radiative efficiency of ultraviolet LEDs is relatively insensitive to injection current. It is expected that shallow potential minima caused by indium fluctuation in high-indium-containing GaInN quantum wells for blue LEDs result in a high radiative efficiency at low injection currents due to the localization of carriers; however, the radiative efficiency decreases rapidly with increasing injection current due to the delocalization of carriers.