Abstract: A unified new approach is proposed for the systematic Derivation of various simplified Gurtin-type variational principles in linear theory of dynamic viscoelasticity. The prime feature of this approach is the use of an important integral relation and generalized Le-gendre transformations given by the author. With this approach, it; is possible not only to derive the complementary functionals for the five-field, four-field, threefield, two-field and one-field simplified,Gurtin-type variational principles, bu...