In this work vibrational-damping properties of a viscoelastic material of a Russian vibration absorber coating named ?kjiG-27? is investigated. For this purpose ASTM E756-05 standard is employed and corresponding experimental tests are performed step by step. This standard test method is useful to obtain vibrational-damping properties of materials and can makes it possible to apply viscoelastic material in passive vibration control applications in a beneficial manner. Since the investigated vibration absorber coating is of type of constrained layer damping or CLD, a sandwich specimen is fabricated according to the standard instructions. Then by performing experimental modal testing on the sandwich specimen and base steel beams as cantilever beams, the desired outputs including variations in loss factor and shear modulus of the viscoelastic material versus frequency are obtained. Also the accuracy of conducted tests are checked out using the standard criteria which the outcomes confirm the validity of tests and results.