Photocatalysis of InGaN nanodots grown on GaN/sapphire templates by metal organic vapor phase epitaxy is studied.Photodegradation of methylene orange by InGaN nanodots responsive to visible light is observed.Analysis through atomic force microscopy and time-resolved photoluminescence measurements show that wider bandgap of InGaN,larger specific surface area and more proportion of photocarriers diffusing to the surface before recombination are propitious to photodegradation.