In optical scatterometry, the sensitivity has a significant impact on the precision of the extracted structral parameters in addition to the quality of the measured signatures. As the sensitivity of structral parameters can be improved with the proper selection of measurement configuration (a combination of wavelengths, incidence, and azimuthal angles), we proposed a method to determine an optimal one for optical scatterometry based on sensitivity analysis. Experiments performed on a one-dimensional periodic grating show agreement between the theoretically predicted and experimentally obtained optimal measurement configurations, which demonstrates the validity of the proposed optimization method.