Indirubin has been used clinically to treat chronic granulocytic leukemia, but poor solubility limited its absorption in the body. In order to reduce its side effect and raise its therapeutic effect on chronic granulocytic leukemia, six halogen-substituted derivatives were synthesized. Compounds I, II, III and V exhibited higher antitumor activity against L7212 bearing mice and W256 bearing rats than indirubin. In the parallel experiment, the most active compound III showed increase in life-span of mice bearing L7212 by 41-73%, and marked inhibitory action against W256 in rats with the inhibition rates of 48-83%, while indirubin showed 0 and 30% inhibition.