Seven N-acetyl pyrazolines 2a similar to 2g and seven N-acetyl bis-pyrazolines 4a similar to 4g with diphenyl etheryl moiety were synthesized and characterized by H-1 NMR,C-13 NMR, elemental analysis and ESI-MS, and their in vitro antitumor activities on A549, H1299 and MCF-7 were evaluated by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxypheny1)-2-(4-sulfophenyl-2H-tetraiolium) (MTS) assay. The results showed those compounds exhibited potent antiproliferative effects on cancer cells, among them compound 3,3'-(4,4'-diphenyl ether)-5,5'-bi[1-acetyl-5-(benzo[d][1,3]dioxo-5-yl)-2-pyrazoline] (4e) showed significantly inhibited the growth of all three kinds of cancer cells, the IC50 values of A549, H1299 and MCF-7 were 16.91, 10.09, 10.97 mu mol/L, respectively.