Peculiarities of the atomic-layer chemical vapor deposition growth of TiO2 and SnO2 thin films from chlorides and water at low (less than or equal to 300 degreesC) temperatures are in situ monitored on a submonolayer scale by incremental dielectric reflection. RHEED, AES, EPMA, SFM, and UV-VIS spectrophotometry are used for the ex situ characterization of the growth. It is shown that the main peculiarity of the TiO2 growth exhibits itself in the spontaneous crystallization at the very beginning of the deposition while the peculiarity of the SnO2 growth is connected with a low reactivity of water.