The present invention provides a composition for chemical vapor deposition film-formation comprising a borazine compound represented by the Chemical Formula 1 satisfying at least one of a condition that content of each halogen atom in the composition is 100 ppb or less or a condition that content of each metal element in the composition is 100 ppb or less. In the Chemical Formula 1, R.sup.1 may be the same or different, and is hydrogen atom, alkyl group, alkenyl group or alkynyl group, and at least one thereof is hydrogen atom; R.sup.2 may be the same or different, and is hydrogen atom, alkyl group, alkenyl group or alkynyl group, and at least one thereof is alkyl group, alkenyl group or alkynyl group. By using the composition, physical properties such as low dielectric constant property and mechanical strength of the thin film produced from a borazine-ring-containing compound can be improved. ##STR00001##