The luminescence property of the hexagonal boron nitride (h-BN) thin films grown on c-plane sapphire substrates by chemical vapor deposition using BCl3 and NH3 as sources was characterized by cathodoluminescence (CL). The intensity of the emission band located at 214 nm, which can be ascribed to the recombination of free excitons of h-BN by comparison with that of the h-BN bulk crystal, increased with decreasing a reactor pressure from 20 to 5 kPa at a growth temperature of 1200 C. The influences of growth reaction and film formation on the film quality were discussed in terms of the observed CL properties and its dependence on growth conditions.