In the proposed method space and time temperature gradients are used for GaAs epitaxial deposition on Si substrates from liquid phase. Minimal Si substrate dissolution and preferential GaAs deposition from the liquid phase on Si substrate can be obtained by selecting dissolvents, requiring necessary gradients temperature values and times of active phases interaction. Because of nonuniformities in the etched Si substrate surface act as crystallization centres, the deposition process begins from GaAs island growth. Due to the dominate tangential growth rate, the separate single crystals coalesce into a GaAs monolayer.