A novel apparatus forthe studies of transient absorption spectroscopy and photo-induced reaction dynamics wasdeveloped recently. The unique characters was outlined as follows. A wide frequency-tunable laser system (4μs～200nm)with low flux was used as photolysis source. Transient species produced by laserphotolysis andor photochemical reactions can be detected by transient absorption spectra.Dynamic behavior involving radical reaction have been proved by this equipment.