Chrysanthemum indicum Linné (CI) has a long history for the treatment of inflammation, hypertension and respiratory diseases in China. The purpose of the present study was to investigate the anti-inflammatory and immunomodulatory properties of the inflorescence or bud of CI extracts. The ethanol extract of CI (CIEE) was fractionated to a petroleum ether soluble fraction (CIPF), an ethyl acetate soluble fraction (CIEF), a butanol soluble fraction (CIBF) and a water soluble fraction (CIWF) successively. CIBF (150 mg/kg, p.o.) caused a significant inhibition on the auricle edema in mice. CIBF (150, 300 mg/kg, p.o.) not only significantly increased the delayed-type hypersensitivity (DTH) reaction induced by 2,4-dinitro-fluorobenzene (DNFB) but also significantly enhanced antibody generation by splenic cells of mice and IgG and IgM levels in mice sera in response to sheep red blood cells (SRBC) in cyclophosphamide (CP)-induced mice. Furthermore, CIBF (150, 300 mg/kg, p.o.) obviously potentiated the function of the mononuclear phagocytic system in CP-induced mice. The above results reveal that CIBF possesses anti-inflammatory, humoral and cellular immunomodulatory and mononuclear phagocytic activities, probably due to the presence of flavonoids.