Hot water (JLW) and 70% ethanol (JLE) extracts of jujube leaves were investigated for their antioxidant effect, cytotoxicity, and anticancer effects. The measured content of total polyphenolics in JLW and JLE was $200.4mg{cdot}g^{-1}$ and $234.6mg{cdot}g^{-1}$, respectively. Extracts showed 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of 91.8% (JLW) and 93.8% (JLE) at $1,000{mu}g{cdot}mL^{-1}$. A radical scavenging activity of JLW and JLE was higher than that of Vitamin C (89.3%) (at $1,000{mu}g{cdot}mL^{-1}$). Results from the analysis of Super oxide dismutase (SOD)-like activity showed 33.9% for JLW and 34.8% for JLE (at $1,000{mu}g{cdot}mL^{-1}$). Extracts showed no cytotoxicity in a normal human cell line, HEK293. In human cancer cells JLW extract showed higher antiproliferative activity than JLE extract. Inhibitory effect of JLW for human breast cancer cells (MCF-7), human stomach cancer cells (AGS), human lung cancer cells (A549) and human liver cancer cells (HepG2) growth was 16.9%, 61.3%, 57.7%, and 20.1% respectively, at $1,000{mu}g{cdot}mL^{-1}$. The results of our study suggest the potential use of Zizyphus jujube leaves extracts for use as an excellent antioxidant and antiproliferative substance.