Abstract: OBJECTIVE To compare the effects of each component of Tripterygium wilfordii column chromatography on the expression of tumor necrosis factor-alpha(TNF-α) and interleukin-1β(IL-1β) in the serum of rats with type Ⅱ collagen- induced arthritis(CIA), and to explore the relationship between effective components of each component and their pharmacology effect. METHODS HPLC was used to determine the content of 6 effective components in each component. Bovine collagen Ⅱ(BCⅡ) emulsion was injected into the dorsal, tail and left posterior plantar plantaris of SD rats, and the rat model of CIA was established. After successful modeling, eighty CIA rats were selected and randomly divided into model control group, positive control group and groups of each component, with 8 rats in each group. After twenty days of immunization, rats were given intragastric administration for 3 weeks, the rats' arthritis index(AI) was recorded. The expression of TNF-α and IL-1β in serum was detected by enzyme-linked immunosorbent assay. In situ TUNEL assay was used to detect the effects of different components on hepatocyte apoptosis. Western-blot was used to detect the expression of caspase-3 protein in rats' liver. RESULTS The contents of effective components in the middle and the last components were quite different. Compared with the model control group, the high and low dose group of the middle components and the high dose group of the last components could obviously reduce the AI value three weeks after administration(P<0.01), inhibit the expression of TNF-α and IL-1β in the serum of rats(P<0.01), induce hepatocyte apoptosis(P<0.01), and increase the activity of caspase-3(P<0.01). CONCLUSION Each component of Tripterygium wilfordii column chromatography has therapeutie effects on CIA rats, its mechanisms may be related to the reduction of the expression of TNF-α and IL-1β in the serum, the rat hepatocyte apoptosis can be induced and the activity of caspase-3 can be up-regulated after gavage, there is a dose-effect relationship between effective components and pharmacology effect.