The growth of nanoparticles embedded in a host matrix can lead to substantial strain. Strain can have much influence on the crystal growth and microstructure development of nanoparticles and thecorrelation of the physical properties of nanoparticles with their microstructures. To better understand and control the physical properties of GaAs nanoparticles, it is fundamentally necessary to study the strain distribution of nanoparticles embedded in different thin films.In this paper, the growth strain of GaAs nanoparticles embedded in Al2O3 and SiO2 thin films were investigated. Finite element calculations clearly indicate that the GaAs nanoparticles incurs a net deviatoric strain in both amorphous Al2O3 and SiO2 thin films. The compressive strain existing in the center of a GaAs nanoparticle embedded in Al2O3 thin film is stronger than that at the surface of the nanoparticle. In contrast, the compressive strain existing at the surface of a GaAs nanoparticle embedded in SiO2 thin film is stronger than that in the center of the nanoparticle. It is possible to control the strain distribution of GaAs nanoparticles by embeding the GaAs nannoparticles in different thin films, which will futher influence the microstructures and morphologies of GaAs nanoparticles. Strain engineering is an effective tool for tailoring the properties of GaAs nanoparticles.