[en] A treatment of kinetic Monte Carlo method is devised that incorporates strain effects in a direct and natural way. The submonolayer growth (θ<0.3) of islands, in the cases of negative misfits (-10% and -32%) and of positive misfits (+10%, +20%, and +32%), is considered. The case of negative misfits leads to smaller islands, whereas the case of positive misfits leads to larger islands. It is inferred, from these drastic effects of strain on heteroepitaxial nucleation, that the adatom, at low coverage (θ<0.3), is subject, during the growth regime (0.05<θ<0.2), to a bias force generated by compressive or tensile strain at interface, which promotes detachment or attachment from islands, respectively. copyright 1999 The American Physical Society