This essay begins from affirming taxation credit thesis , bringing up a proposal what taxation credit definition and classify are . it puts system economics principle to use , setting taxation credit of science . it announces taxation credit is a very important thing in formulating government revenue and expenditure and debasing trade expenses and reducing taxation shifting , therefor , it will have practical significance in research taxation credit to perfect taxation system and advance taxation be run according to law 本文从税收信用理论的界定入手，提出了税收信用的定义和分类；运用制度经济学原理，对税收信用进行了科学的定位，揭示了税收信用在规范政府收支、降低交易费用、减少税收流失等方面的重要作用，以及研究税收信用对于完善税收制度、推进依法治税的现实意义。
