Kinetics of phase growth in multiphase Cu-Sn and Ni-Sn systems and effect of third substitutive component (Ni or Cu respectively) were studied experimentally in temperature range 160-220oC and analyzed theoretically. Kinetic equations for calculation of diffusion coefficients in growing competitive phases were obtained. It was found that the substitutive components accelerated phase growth lowering the values of diffusion activation energy and pre-exponential factor. As a result the growth rates of competitive phases Cu6Sn5 and Cu3Sn in Cu-Sn system changed with substitutive Ni so, that only one (CuNi)6Sn5 phase survived whereas (CuNi)3Sn phase was suppressed. Obtained results are discussed in terms of higher disordering caused by substitutive components in ternary phases as compared with binary ones.