Laser flash photolysis technique was used to study photo-chemical mechanism of CS,2, under the excitation of 308nm laser and determine related rate constant involved in excitation of carbon disulfide (CS,2,). The laser flash photolysis showed that the excited triplet of CS,2, could be quenched by its ground state to generate CS,2, free radical intermediates. Meanwhile, rate constant for the quenching was also obtained. The radical cation and anion of CS,2, produced in laser flash photolysis were further confirmed by pulse radiolysis with their characteristically transient absorption. Results presented in this paper may support the direct evidence for the hypothesis of CS,2, oxidative injury to biologic tissue.