<p><b>OBJECTIVE</b>To observe the efficacy and safety of Danlong Oral Liquid (DOL) combined Western medicine (WM) in treating mild-to-moderate bronchial asthma patients (heat wheezing syndrome) at acute onset.</p><p><b>METHODS</b>Totally 480 mild-to-moderate bronchial asthma patients (heat wheezing syndrome) at acute onset were randomly assigned to two groups in the ratio 3:1, the treatment group (360 cases) and the control group (120 cases). All patients received basic WM treatment. Patients in the treatment group took DOL, 10 mL each time, 3 times per day for 7 days in total, while those in the control group took Kechuanning Oral Liquid (KOL) , 10 mL each time, 3 times per day for 7 days in total. Efficacy for asthma symptoms, lung functions and scores of TCM syndrome and/or main symptoms were evaluated.</p><p><b>RESULTS</b>The percentage of clinical control and significant effectiveness of asthma symptoms in the treatment group was significantly higher than that of the control group (77.36% vs 56.07%, P < 0.01). The percentage of clinical control and significant effectiveness of lung functions in the treatment group was significantly higher than that of the control group (74.28% vs 50.00%, P < 0.01). The anterior-posterior difference in scores of TCM syndrome was significantly superior in the treatment group than in the control group (-11.26 ± 4.70 vs -9.21 ± 5.09, P < 0.01). The anterior-posterior difference in scores of main symptoms was significantly better in the treatment group than in the control group (-6.58 ± 3.08 vs -5.16 ± 3.45, P < 0.01). The incidence of adverse reactions was significantly lower in the treatment group than in the control group [1.73% (6/346 cases) vs 10.17% (12/118 cases) , P < 0.05].</p><p><b>CONCLUSION</b>DOL combined WM was superior to KOL in treating mild-to-moderate bronchial asthma patients (heat wheezing syndrome) at acute onset.</p>