(111) silicon is widely used in current microstructures. In this study, theoretical analysis shows that different states of elastic stress may result in different eigenvalues and their respective eigenvectors of the lattice dynamics secular equation. The key point in determining the spectral character is to obtain the Raman tensor corresponding to each eigenvector whose eigenvalue can be represented by a function of the stress tensor components. As examples, the wavenumber–stress factors under some specific states of stress at typical polarization configurations were determined. Finally, a calibration experiment was performed to validate the theoretical prediction.