BACKGROUND: RANTES is associated with chemotaxis and activation of eosinophils. RANTES is up-regulated in allegic inflammation and play a critical role in the pathogenesis of allegic inflammation. Recently, circulating form of RANTES have been identified in the peripheral blood. METHOD: In the present study, we measured soluble RANTES levels in 17 patients with atopic brochial asthma (8 patients: early response to allegen challenge, 8 patients: early and late response to allergen challenge) on 30mins, 2hrs and 8 hrs after allergen challenge with house dust mite, prechallenge period. RESULT: RANTES levels in sera from patients with bronchial astma in prechallenge conditions were higher than in normal control subjects. But, RANTES levels in sera from patients with bronchial asthma in 30mins, 2hrs and 8hrs after challenge were no significantly higher than prechallenge conditions. CONCLUSION: These results suggest that RANTES plays a role in the pathogenesis of patients with atopic bronchial asthma and may be related to persistence of subclinical allergic inflammation.