The vapor of monomer, Si(Pc)(OH)(2), is deposited onto the (100) face of NaCl single crystal which is heated at 350 degreesC under a dynamic vacuum of 10(-3) Pa. Epitaxial crystallization occurs on the substrate, and condensation polymerization takes place in situ at the same time. The resulting product is a kind of nanocrystalline film of [Si(Pc)O](n) that is composed of crystalline grains with a size of about 10 nm and a lot of defect regions without thermal energy stored in them, which differs from semi-crystalline polymers. The high-resolution electron microscope observations indicate that the nanocrystalline films of the polymer have something in common compared with nano-metals. (C) 2001 Elsevier Science Ltd. All rights reserved.