Abstract: The individual income tax system is an important tool for the government to regulate and redistribute taxpayers’ incomes justly. Besides, there is a social focus on the problem of fairness of the deduction standard of personal salary and bonus during China’s individual income tax reform. The quantitative analysis of effects of individual income tax reforms in 2008 and September 2011 in our country shows that the income gap between unfair distributions cannot be narrowed only by continuously improving the working deduction standard. Only through a combination of basic and additional deductions based on a comprehensive income tax system can we give full scope to the function of the fair social wealth allocation of income tax in China.