Bronchial asthma is a chronic airway inflammation disorder involving lymphocyte activation and various cytokines secretion by lymphocyte. The inflammatory response results from a complex network of interactions between inflammatory cells (mast cells, eosinophils, macrophages) and resident cells belonging to the lung structure itself like EC, fibroblasts, or bronchial epithelial cells. IL-6 which is known to up-regulate the endothelial cell expression of adhesion molecules participating in the development of the inflammatory reaction in bronchial asthma is produced by alveolar macrophage. ICAM-1 is produced by bronchial epithelial cell and expression by endothelial cell, which is known to enhance of the influx of various cells, RANTES which is known to a potent chemoattractant for eosinophils, lymphocytes, and monocytes, a member of the CC chemokine family, is expressed by bronchial epithelial cell. To evaluate whether markers of lymphocyte activation are useful markers of disease activity in bronchial asthma, we measured slL-6, sICAM- 1, sRANTES in 42 patients with mild to moderate bronchial asthma and in 26 normal controls and con the result with other disease activity markers in asthma(pulmonary function, blood eosinophil counts). The mean level of sIL-6 was higher than that of normal control and correlated significantly with sICAM-1, FEV1% to predicted value. The mean level of sICAM-1 was higher than that of normal control and correlated significantly with FEV1%, FEV1% to predicted value. The mean level of sRANTES showed the tendency to be higher than that of normal control, but not significant statistically, and did not correlated with sIL-6, sICAM-1, FEV1%, FEV1% to predicted value, blood eosinophil counts. It appeared that sIL-6 and sICAM-1 could be a disease marker in bronchial asthma. But, clinical application of the measurement of these markers needs to be studied further.