The effects of introducing boron (B) on the growth of Ge islands are studied and quite small Ge islands were found to appear in the presence of B adlayer. On the other hand, cosupply of Ge and B brought no change in the island size and the decrement of the number of Ge islands. The average of lateral size and height of these small islands are 30 and 1.5 nm, respectively, and the density is 1.4 x 10(10) cm(-2) which is much higher than that of typical Ge islands. These results indicate that pre-deposition of B can produce preferable surface morphologies that small Ge islands can be easily formed.