Abstract: Objective To observe the role of theophylline in relieving airway symptoms and inflammation in patients with mild asthma.Methods Fifty-six patients with mild asthma were randomly divided into treatment group(n=41) receiving oral theophylline at daily dose of 4 to 6 mg/kg for 16 weeks and control group(15 cases) without medication other than β2 antagonist,which was administered when necessary in both groups.Peripheral blood T-lymphocyte subsets(CD3+,CD4+,and CD8+) and pulmonary function(PEFam and PD20) before and at 8 and 16 weeks during treatment were measured.Results Significant difference was observed in CD3+ and CD4+ T-lymphocyte subsets after medication with theophylline(P<0.05) in the patients,and PEFam and PD20 were also significantly different from those of the control group(P<0.05).Theophylline significantly improved the clinical symptom scores(P<0.05) and decreased the asthma attacks.Conclusion Low-dose oral theophylline may significantly relieving airway inflammation in patients with mild asthma