Let F be an arbitrary field of characteristic different from 2 and 3, and C be field of complex numbers. Suppose that T2(F) and T2(C) are the algebra of 2×2 upper triangular matrices on F and C respectively. If A∈T2(F) satisfies A3 = A, then A is called a tripotent matrix. If A∈T2(C) satisfies Ak = A, then A is called a k-potent matrix, where k≥3. We use T and T2k(C) to denote the subset of all tripotent matrices in T2(F) and T2(C) respectively. We will determine all injective mappingsφof T2(F) which satisfies if A -λB∈T thenφ(A) -λφ(B)∈T, (?)λ∈F, and A, B∈T2(F). Denote the set of all such mappingsφasΦ(F). A map is called to be preserving k-potent if it satisfies A-λB∈T2k(C), thenφ(A) -λφ(B)∈T2k(C), (?)λ∈C, and A, B∈T2(C). We useΦ(C) to denote the set of all injective mapsφfrom T2(C) to itself which preserving k-potent.In the chapter l,we give a brief introduction to additive,multiplicative,linear preserver problems and A -λB preserver problems. In the chapter 2, the forms of the injective maps from T2(F) to T2(F) preserving tripotent are characterized. In chapter 3, the forms of the injective maps from T2(C) to T2(C) preserving k-potent are characterized.Symbol Eijstands for the matrix having the (i,j)-th entries equal to one and all other entries equal to zero, AT stands for the transposition of A and I2 stands for the identity matrix in T2(F). Denote the set {1, 2,…, n} as [1,n] and A as {ε| sk-1 = 1}. The mapφis bijective which is from [1,n] to [1,n]. (?) stands for the conjugate of A. A* stands for (?) called conjugate transpose of A. R(X) stands for spectrum radiux of A. GLn(F) is general linear group over F. |