The following problems are discussed in this paper:

• Incident and reflected wave field of wave guides: Both case of a P wave pulse grazing incidence and a SV wave pulse incident at the critical angle _c are observed by photo elastic methods. We interpret the grazing P wave pulse becoming series of P and SV wave group at both lateral free surface.

• The testing principle and method: The mechanism of testing elastic moduli of workpiece material (plates, cylinders, pipes) is interpreted.

  Some testing formulas are given, including longitudinal wave speed C₁; transverse wave speed C _t ; shear modulus G; Young's modulus E; Bulk modulus K;

• The testing system: . The testing construction and instrument accuracy requirement are given.

• The testing results and discussion: Some testing results of plates and cylinders are given (including steel; cast iron; brass; plexiglass). The applications of testing material properties are discussed.