The principles that show the constitutional essence of taxation law rules are the ones of taxation fairness and lawful determination of taxation.

Using an extended tax-smoothing model,it empirically studies the relationship between seigniorage and tax-smoothing criteria in China, which denies the tax-smoothing hypothesis.

But very difficult maintenance allotment fair;On the other hand, Cancel the agriculture tax, farmer imperfection pay tax the duty, disobey the revenue from tax fair.

Owing to in the pretax deduction model of individual income tax in China, the taxpayer s natural condition and family burdens was completely neglected, the principle of tax equity is violated which affects our great target on establishing harm.

It is necessary to construct a harmonious society exerting tax function on income redistribution,in order to realize tax equity and upgrade social equity.

In this paper,the connotation of the reven ue made by a fair interpretation of the expansion of that tax fairness should include the contents of the three levels,namely,the nature of tax fairness,tax equity and revenue generation within the intergenerational equity,also known as the"three-level" view of tax fairness.