The invention provides a composition for clearing heat, removing toxicity and protecting the liver. The effective ingredients of the composition comprise radix isatidis, selfheal, Wanniangan and strigose hydrangea juvenile leaf in a weight ratio of (1-20):(1-10):(1-5):(1-2). The composition is prepared by combining strigose hydrangea juvenile leaf, radix isatidis, Wanniangan and selfheal, has the effects of clearing heat, removing toxicity, moistening the lung, relieving sore-throat, eliminating phlegm, relieving cough, promoting secretion of body fluid, clearing and protecting the liver and the like, is mainly used for treating epidemic heat syndrome, eyeball nyctalgia and dizziness, and has a remarkable effect on inhibiting various viruses and bacteria. According to the composition, the defects of the radix isatidis are overcome by the strigose hydrangea juvenile leaf, and the bitter taste and cold property of the radix isatidis and the cold property and bitter and spicy taste of the selfheal can be relieved by utilizing that the strigose hydrangea juvenile leaf is cool in property and sweet and mild in taste and the Wanniangan is sweet in taste and cool in property. The invention further provides a method for preparing the composition for clearing heat, removing toxicity and protecting the liver.