The radiolysis of air-free CC1₄ has been well investigated.Using D.P.P.H.Bra or HI as "scavenger",the G value of the radicals and the "moleonlar" products have been determined.But the mechanism of radiolysis of CCl₄ in the presence of air is still not clarified.The main diffionlty is that the G valve of the bank reaction CCl₃+Cl₂→CCl₄+Cl during irradiation has not been determinod.It is impossible to compare the yield of chlorine with G_R value obtained by D.P.P.H method,and to carry out kinetic oalonlations.