In the present paper, after middle pressure chromatograph separationusing both positive phase and reversed-phase conditions, the organic additives inethylene-propylene rubber were identified by infrared spectrometer. At the sametime, by using solid phase extraction column to maintain the main component-fueloil in organic additves to avoid its interfering with minor compounds, otherorganic additves were separated and analysed by GC/Ms. In addition, the remainingactive compound such as benzoyl peroxide was identified by CC/Ms, throughanalyzing acetone extract directly. Using the above mentioned techniques, softenagents (fuel oil, plant oil and phthalte), curing agent (benzoylperoxide),vulcanizing accelerators (2-mercaptobenzothiazole, ethyl thiuram and butylthiuram), and antiagers (2,6-Di-tert-butyl-4-methyl phenol and styrenated phenol)in ethylene-propylene rubber were identified. Although the technique wasestablished in ethylene-propylene rubber system, it can be used in other rubbersystem.