This article is devoted to consideration of a phenomenon of stability of a tax system in the context of sustainable development. The definition "stability of a tax system" is concretized. Development of the conceptual framework allowing to consider stability of a tax system as the difficult system dynamic and spatial phenomenon, to analyze and predict nonlinear processes of accumulation of potential imbalances in a tax system is offered. The approach consisting in allocation and differentiation in the definition "stability", both stability of a state, and stability of development is reasonable.