Objective: This study was designed to evaluate the effect of the antipyretic effective fraction from the decoction of Bupleurum chinese and Scutellaria baicalensis in fever model mice induced by lipopolysacharide(LPS). Method: Four fractions were obtained by using AB-8 macroporous resin column to purify the decoction of B. chinese and S. baicalensis . Through chemical reactions to dentify the major types of components

the flow of a merger similar gain four parts.Then the anus temperature of mice was tested to observe the antifebrile action of every fraction and compare to the fever model mice induced by LPS. Result: The four fractions

A (polysaccharides)

B (saponins)

C (saponins and flavonoids)

D (flavonoids and aglycones of saponins)

purified by AB-8 macroporous resin

all can reduce the temperature of fever mice (P<0.05)

and diferent fraction have differen levels. Fraction D showed the best effective on antifebrile action(P<0.01). Conclusion: the decoction of B. chinese and S. baicalensi s involved more than one effect of the fever effective fractions.