A new approach to measure the optical second-order nonlinear coefficient tensor of material which is difficult to prepare as a large single crystal is demonstrated. In such a case, due to the limitation of the crystal direction the Maker fringe measurement cannot provide each tensor component but instead yields an effective value. A technique using the second-harmonic generation with evanescent wave (SHEW) makes up for the Maker fringe result. We have applied the measurements to the organic material 4-nitro-2-ethoxyamide-4′benzyloxytolane (NEBT). The combined results from different measurements clarify the nonlinear optical character of NEBT molecules and the largest component of the optical second-order coefficient tensor was obtained to be 39±8 pm/V. The combination of the Maker fringe and the SHEW technique can be a powerful tool. ©1997 American Institute of Physics.