Field of invariants of Borelean group of adjoint representation of $GL(n,K)$

The paper is devoted to invariant theory problems, in particular to the problem of finding generators of invariant fields in an explicit form. The set of generators is given for invariant field of unitriangular group concerning the adjoint representation of $GL(n,K)$ group. Moreover, the set of generators of Borel group for the field of invariants is constructed and their algebraic independence is proved.