Self-assembled In0.22Ga0.78As quantum dots (QDs) fabricated on Si substrate with Ge buffer by metal organic vapor phase (MOVPE) were investigated. Transmission electron microscopy (TEM) and Atomic force microscopy (AFM) images were used to observe the size and distribution of the In0.22Ga0.78As QDs grown on the GaAs/Ge/GsSi/Si layer structure. The influence of the growth temperature on the QDs density and distribution was investigated. For QDs grown at 430°C, the density of the In0.22Ga0.78As dots was estimated to be 1×10 11 cm-2 and the In0.22Ga0.78As. QDs thickness was 5 monolayer thick.