1. The system of negative income tax was firstly proposed by Milton Friedman of Chicago University, and developed by economists in the west later.

2. Organically combined with social welfare system, negative income tax is one kind of the effective mechanism, providing the payment voluntarily to the poor under certain level of income.

3. Any proposal for a negative income tax must have at least three elements-an income floor, a marginal tax rate, and a cutoff point.

4. Thus, Pass to promote the negative income tax system, make"low protect"change into" negative tax ".

5. Negative Income Tax A taxation system where income subsidies are given to persons or families that are below the poverty line.

6. Realize true fairness allocation, need to use negative income tax system when necessary.