Antiviral Oral Liquid (AOL) is an adult medicine in the Chinese Pharmacopoeia used to treat upper respiratory infections such as influenza. It has shown promising clinical efficacy in relieving flu-like symptoms such as fever, inflammation, and pharyngalgia both in adults and children. However, the instruction manual does not specify the exact usage and dosage of AOL for children. In this article, we set 6 dosage ranges: 0.2, 0.5, 0.7, 0.9, 1.1, 1.4 mL/kg/d, according to its dosage for adults and the conversion method between adult and children dosage. And six animal models were used to evaluate the effectiveness of AOL in different doses. The results indicated that AOL could reduce the lung index, virus load, and expression of proinflammatory cytokines in the lung. AOL could improve pathological changes and prolong the survival time of mice infected by the Influenza A virus (H1N1) A/PR/8/34 strains at 0.5-0.9 mL/kg/d concentrations in different degrees. The four dose groups of 0.7-1.4 mL/kg/d could significantly inhibit the ear shell swelling caused by xylene and reduce the rabbit body temperature induced by lipopolysaccharide (P < 0.01, P < 0.05). All the five dosage groups of 0.2-1.1 mL/kg/d could inhibit the increase of peritoneal capillary permeability induced by glacial acetic acid (P < 0.01). AOL at 0.7 and 0.9 mL/kg/d reduced the painful writhing times in young mice induced by glacial acetic (P < 0.01). These results indicated that the optimal dose of AOL in antiviral, antipyretic, anti-inflammatory, and analgesic effects is 0.7 mL/kg/d.