Abstract: A computational method is developed to solve engineering problems for the viscoelastical damping structure attached to gears,and a simple model is setup by combining 20-node element technique according to the modal strain energy theory.Thus,a practical and simple approach for engineering application is provided to predict loss factors and optimal location of damping layer in the structure without the difficulty of solving complex eigenvalues.As an example,the loss factors and optimal damping location have been calculated for a real gear.The results are in a good agreement with its experimental data.