Interest income tax is an important political tool for Chinese government to regulate the consumption of residents, which has a certain effect on the relationship between saving and consumption. It is worthwhile to further discuss the effect of interest income tax on income redistribution in China, especially from the empirical perspectives. From the angles of average tax rate progressiveness and pre-tax and after-tax Gini coefficient, the effect of interest income tax on income redistribution is theoretically analyzed. Empirically, the effect is tested using the survey data of urban residents from 2000 to 2007. The results are as follows: First, the average rate of interest income tax is progressive among different income groups, therefore has a positive effect on income redistribution. Second, the Gini coefficient of after-tax interest is less than the pre-tax Gini coefficient: it is meant that the interest income tax has the effect for reducing income gap. Third, there are differences of the effect in the various periods. Fourth, reducing the rate of interest income tax weakens the income redistribution effect of interest income tax.