Abstract: Considering the opening and closing conditions of cracks, the explicit formulation between the bending curvature of a viscoelastic Timoshenko beam with switching cracks and bending moment is derived by using the creep modulus and generalized Dirac delta function. The criteria for the opening and closing conditions of cracks is presented for the viscoelastic cracked beam subjected to a uniform sudden load. Furthermore, the bending deformation of a simple-supported viscoelastic Timoshenko beam with switching cracks is discussed by numerical examples.