The geometrical configurations of (100)-oriented (Si)n/(Ge)n (n = 1-6) strained superlat-tices on Si1-xGex(x = 0-1) substrates are calculated by using Keating model. The influence of substrate on the growth of the superlattices is discussed. The calculations indicate that proper choice of substrate Si1-xGex is beneficial to the growth of (Si)n/(Ge)n superlattices.