RF-MBE growth of GaInNAs systems on GaAs(0 0 1) substrates and Raman characterizations of the local structures of the grown layers have been investigated. Indium beam irradiation during the GaInNAs growth has a strong influence on the nitrogen incorporation to the grown layers. Raman scattering measurements have revealed that the formation of ordered domains such as (GaN)(GaAs) natural superlattice cluster in the GaInNAs layers is suppressed by the In incorporation..