The Raman spectra of gaseous products formed in radiation of two polymers, polydimethylsiloxane (PDMS) and polyethylene (PE) , have been studied in this paper. They are typical polymers which mainly crosslink during irradiation by ,60,Co gamma rays. At first, the Raman spectra of pure methane, ethane and hydrogen were detected in the 50 ml analogue tube (Fig. 1-b) , and three spectrum peaks at 2917 cm,-1, 2954 cm,-1, and 4157 cm,-1, were obtained. Their intensities depending on contents of methane, ethane and hydrogen in the analogue tube are shown in Fig. 2. The results prove that intensity of Raman spectra of each gas is only related to its absolute content in the airtight vessel that has fixed volume and is not related to other gaseous contents in the same vessel. Then, two grams of PDMS are put in each of six 50 ml sample tube respectively (Fig. 1-b) and are radiated by various doses in vacuum. The Raman spectra of gaseous products formed in radiation of PDMS is shown in Fig. 3. After that, the intensities of Raman spectra at 2917 cm,-1, 2954 cm,-1, and 4157 cm,-1, were compared with each corresponding standard curve in Fig. 2 and the amount of each component and total amount of gaseous products produced in irradiation of PDMS were estimated(see Tab. 1) . The radiation chemical yields (G Value) for gaseous products formed in radiolysis of PDMS at various doses can be calculated from equation (1) and are given in Tab. 2. The results indicate that the G values of total gaseous products and of each component are not changed with doses. The average values of G are G (total) =1,86; G(CH,4,) =1.05; G(C,2,H,6,) =0,23 and G(H,2,) =0,58. From the mechanism of dimolecular reaction, the results given in Tab. 2 and Fig. 4 were satisfactorily explained by using dynamic method. Finally, the radiation chemical yield of hydrogen produced in radiolysis of PE is also obtained, G(H,2,) =2.7.