The present invention discloses a pharmaceutical composition and applications thereof. The pharmaceutical composition comprises an extract of Antrodia cinnamomea fruiting bodies and a pharmaceutical carrier. The extract is fabricated via soaking the powder of Antrodia cinnamomea fruiting bodies in hot water and then undertaking extraction with a low-polarity solvent to acquire the extract from the soaked powder. The pharmaceutical composition can function as an adjuvant drug of chemotherapy drugs to enhance the treatment effect of the chemotherapy drugs cisplatin and gemcitabine and relieve the chemotherapy drug-induced side-effects of hair loss, muscle degradation and atrophy, gastrointestinal lesion, nephritis and renal injury.