Objective To test the antiviral and antibacterial effects of Xiaoer Resuqing syrup. Methods The cell culture method was used to calculate the half?inhibition rate of Xiaoer Resuqing syrup against the virus, and the animal model of pneumonia was established to calculate the effect of Xiaoer Resuqing syrup on the lung index and lung inhibition rate of pneumonia mice. Twofold dilutions of syrup were analyzed in vitro in terms of the minimal inhibitory concentration and cumulative inhibitory rate on Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Beta?hemolytic Streptococcus, and Staphylococcus epidermidis. To test the effect of Xiaoer Resuqing on mortality of mice infected with Staphylococcus aureus in vivo. Results In vitro antiviral experiments showed that Xiaoer Resuqing syrup completely inhibited cytopathic effects induced by influenza virus and respiratory syncytial virus when diluted 32 times. In vivo studies also showed that the administration of 20 and 40 mL/ kg Xiaoer Resuqing syrup to influenza virus?infected mice had significant effects on lung injury ( P < 0. 05). An in vitro antibacterial experiment showed that twofold dilution of Xiaoer Resuqing syrup reduced the numbers of six bacteria by more than 90%. In mice infected by Staphylococcus aureus and administered the syrup at 40 mL/ kg, mortality was completely avoided. Conclusions The antipyretic and antibacterial result of Xiaoer Resuqing syrup showed that this syrup has certain antiviral and bacteriostatic effects both in vitro and in vivo.