This paper studies type-2 fuzzy rough sets based on the type-2 fuzzy relation. Firstly, the upper approximation
and the lower approximation of type-2 fuzzy sets of a type-2 fuzzy approximate space are defined. Then, basic properties of type-2 fuzzy rough approximation operators are derived, and the fact that type-2 fuzzy relation having special property can be characterized by the essential properties of these operators is discussed. Finally, type-2 fuzzy rough approximation operators are defined by axioms.