Self assembled In0.6Ga0.4AsN/GaP quantum dots (QDs) were grown by solid source molecular beam epitaxy (SSMBE). Structural and optical properties of as-grown and annealed In0.6Ga0.4AsN/GaP QDs were investigated. Cross sectional high-resolution transmission electron microscopy (HR-TEM) study did not show any structural defects and N-related chain structures. The integrated PL intensity at 725 degrees C rapid thermal annealing (RTA) for sample prepared at RF power of 390 W was obtained 3.7 times higher than the as-grown sample measured at 18 K. The blueshifts of similar to 0.35 and similar to 0.55 meV/degrees C were observed annealed up to 725 and 800 degrees C, respectively as compare to as-grown samples. Average QD height was reduced from 5 to 3 nm, which may be due to interdiffusion of In and Ga atoms. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim