The current study was carried out to determine the effects of the seed, flesh (seedless fruit), and leaf of loquat (Eriobotrya japonica Lindle.) on antioxidative activity and anti-proliferation in human cancer cells. Total polyphenol contents of loquat seed, flesh, and leaf ethanol extracts were found to be 17.77, 32.32, and 28.08 mg/g, respectively. Also, total flavonoid contents of loquat seed, flesh, and leaf ethanol extracts were found to be 18.77, 28.73, and 21.35 mg/g, respectively. The IC 50 values of DPPH hydroxyl scavenging of loquat seed, flesh, and leaf ethanol extracts were 0.049, 0.063, and 0.042 mg/mL, respectively. Antioxidative indexes of loquat leaf and seed ethanol extracts was highly and it was similar to the BHA and BHT. The antioxidative activities in loquat seed and leaf ethanol extracts were higher in loquat flesh. The antiproliferation effect of loquat seed and leaf ethanol extracts on liver cancer cell line (H460), stomach cancer cell line (AGS) and lung cancer cell line (A549) showed higher values compared with the flesh ethanol extracts. These results indicate that loquat ethanol extracts may play a positive role in antioxidative properties and cancer prevention.