A method of evaluating effects of lapatinib on treating liver cancer is disclosed. The method comprises: obtaining a liver cancer sample from a patient, determining gene expression level of ErbB3 gene in the liver cancer sample, collating gene expression level of the ErbB3 gene in a normal sample, and evaluating effects on treating liver cancer according to gene expression level difference of the ErbB3 gene between the liver cancer sample and the normal sample.本發明係關於一種評估拉帕替尼於肝癌療效之方法,係包含:由肝癌患者取得一肝癌檢體;於體外測定ErbB3基因於該肝癌檢體之表現程度;對照正常檢體中該ErbB3基因之表現程度;依據該ErbB3基因於該肝癌檢體之表現程度,作為預測拉帕替尼於肝癌療效之判斷依據。