Objective: To investigate the effects and mechanism of Xiao Fengsan Granules(XFG) on delayed type hypersensitivity(DTH). Methods:In mice DTH induced by 2

4-dinitroflurobenzene(DNFB)

the effects of XFG on ear swelling

spleen index and thymus index were observed

and the splenocytes proliferation induced by Concanavalin A(Con A) or lipoly-saccharide(LPS) were determined; Meanwhile

the cytokines including interleukin-1(IL-1)

interleukin-2(IL-2) and interleukin-4(IL-4) production by tissue of dermatitis were measured. Results:XFG counld inhibit the ear swelling

thymus index

splenn index and the enhanced splenocytes proliferation in DTH mice. XFG could also inhibit the activity of IL-1

IL-2 and IL-4 in tissue of dermatitis. Conclusions: The mechanism by which XFG regulated the immune function might via its regulatory effects on T

B lymphocytes and its inhibitory effects on cytokines production.