Aqueous ethanol extracts prepared from 19 apple (Malus ×domestica Borkh.) cultivars were studied to explore their antiproliferative activity. Half of them showed strong inhibition on proliferation of human leukemic HL-60 cells, while the others were weak. Total polyphenols, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, and total anthocyanins were measured and the results indicated that the antiproliferative activity was more strongly correlated to the polyphenols and radical scavenging activity than to the anthocyanin content. Several polyphenols in `Jonathan' were identified and quantified by high-performance liquid chromatography (HPLC) analysis. Among those compounds found during HPLC, catechin and epicatechin seemed partially responsible for HL-60 antiproliferation. A careful examination on parentage of the apple cultivars tested revealed that `Jonathan' and its progeny showed high antiproliferation toward HL-60. This is the first observation about the relationship between antiproliferative activity and parentage of apples, and the information would be useful to create new apple cultivars that posses more anticancer potential.