It has been investigated that TBP labeled with ,32,p was used as a probe for detecting the excited species of n-hexane produced under γ irradiation of ,60,Co. This paper studies the relationship between the G,(DBP+MBP), and dose of the binary system of n-hexane—TBP. In the condition of extrapolating the dose to zero, the curve and the kinetic equation of sensitization of TBP by n-hexane have been obtained. Theoretical calculation was in harmony with experimental results.,It has been found thatTBP can be sensitized by two species of excited state of n-hexane. The ,G, values of excited n-hexane species equal 1.04 and 0.4 respectively and the life time can be estimated by diffusion controlled rate constant, τ,1,=0.3×10,-9, τ,2,= 0,.,7,×,10,-9,.