A variety of visible fluorescent processes in pure BC13 gas irradiated with TEA CO2 laser radiation are observed. The space, time and spetrum distribution of visible fluorescence, as well as their dependence on the laser energy, the pressure of BC13 gas and other parameters are measured systematically. The visible fluorescent processes in BCl3 gas are discussed by using a simplified dynamical collision model. The analytical expressions for equivalent vibrational temperature and visible fluorescence intensity, and a simple relation Pτdelay= C/K(Tv) are obtained. The calculated values are in agreement with the experimental results.