ObjectiveTo evaluate the safety and efficacy of Chaihu drop-pill in the treatment of common cold (wind-heat syndrome). MethodsA multi-center, double blind, double dummy, randomized controlled trial was conducted. A total of 479 patients with common cold (wind-heat syndrome) diagnosed between February and August, 2011, were randomly divided into two groups:the trial group (n=359) and the control group (n=120). The trial group received Chaihu drop-pill and Yinchai granule analogue three times a day, while the control group received Yinchai granule and Chaihu drop-pill analogue. The therapeutic courses of both groups were 3 days. Clinical symptoms, syndromes, and adverse effects were observed before and after the treatment. Furthermore, blood, urine and stool test, hepatorenal function test and electrocardiogram were also carried out before and after treatment. ResultsAfter treatment, the healing rates of the trial group and the control group were 32.4%, 20.2% (for full analysis set) and 32.6%, 20.5% (for per protocol set), and the overall response rates were 96.3%, 87.4% (for full analysis set) and 96.5%, 87.2% (for per protocol set). There were significant differences between the two groups (P<0.01). No adverse effects were found in the trial. ConclusionChaihu drop-pill is effective and safe in the treatment of common cold (wind-heat syndrome).