In the processes of discrimination between oil-cracked gases and kerogen-cracked gases,Behar and Pinzgofer et al.’s results were adopted in the former researches,in which the ratio of C2/C3 is basically a constant while the ratio of C1/C2 gradually increases in the course of primary cracking of kerogen. Otherwise in the course of secondary cracking of oil,the ratio of C2/C3 increases rapidly while C1/C2 keeps relatively stable. Our study on analogue experiment shows that,whether it is oil or kerogen,in its process of gas generating by cracking,the ratios of C2/C3,C1/C2 or C1/C3 will all be increased with the growth of thermal conditions. In comparison,the ratio of C2/C3,which is affected by genetic type to some comparatively less extent,mainly responds to the maturity of gases,while the value of C2/C3 is about 2,and that of C2/iC4 is about 10,and the corresponding value of Ro is about 1.5%―1.6%. The influence of gas source on C2/C3 is less than that of gas maturity,otherwise C1/C2(or C1/C3) is obviously affected by cracking matrices. The ratios of C1/C2,C1/C3 of oil-cracked gases are less than that of kerogen-cracked gases,under the condition that the ratios of C2/C3 are similar in value,so are the value of dryness indexes. There exists wide diffidence between this view and the former discrimination method in theory. The analysis of the spot sample indicates that we can apply the above basic view to dealing efficiently with the problem of the discrimination between oil-cracked gas and kerogen-cracked gas. In the processes of discrimination between oil-cracked gases and kerogen-cracked gases, Behar and Pinzgofer et al.’s results were adopted in the former researches, where the ratio of C2 / C3 is essentially a constant while the ratio of C1 / C2 in the course of primary cracking of kerogen. Otherwise in the course of secondary cracking of oil, the ratio of C2 / C3 increases rapidly while C1 / C2 keeps relatively stable. Our study on analogue experiment shows that, whether it is oil or kerogen, in its process of gas generating by cracking, the ratios of C2 / C3, C1 / C2 or C1 / C3 will all be increased with the growth of thermal conditions. by genetic type to some comparatively less extent, mainly responds to the maturity of gases, while the value of C2 / C3 is about 2, and that of C2 / iC4 is about 10, and the corresponding value of Ro is about 1.5% -1.6 %. The influence of gas source on C2 / C3 is less than that of gas maturity, otherwise C1 / C2 (or C1 / C3, C1 / C3) is obviously affected by cracking matrices. The ratios of C1 / C2, C1 / C3 of oil-cracked gases are less than that of kerogen- cracked gases, under the condition that the ratios of C2 / C3 are similar in value There is the value of dryness indexes. There exists wide diffidence between this view and the former discrimination method in theory. The analysis of the spot sample says that we can apply the above basic view to dealing efficiently with the problem of the discrimination between oil -cracked gas and kerogen-cracked gas.