The objective of this study was to clarify the effects of dietary vanadium on cell cycle and apoptosis of liver in broilers. Four hundred and twenty one-day-old avian broilers were divided into six groups and fed on a corn-soybean basal diet as control diet or the same diet amended to contain 5, 15, 30, 45, and 60 mg/kg vanadium supplied as ammonium metavanadate for 42 days. As tested by flow cytometry, hepatocytes in G (0)/G (1) phase were significantly increased in number in 45 and 60 mg/kg groups, and hepatocytes in S, G (2) + M phases in 45 and 60 mg/kg groups and the proliferation index of hepatocytes in 30, 45, and 60 mg/kg were markedly decreased when compared with those of control group. At the same time, the percentage of hepatocyte apoptosis was markedly increased in both 45 and 60 mg/kg groups. The results showed that dietary vanadium in the range of 45 ∼ 60 mg/kg caused cell cycle arrest and apoptosis of hepatocytes in broilers.