Article considering the Raman scattering in molecular media. Applying two laser fields in a two-photon resonance with vibrational transition, the authors study the role of rotational levels for excitation of vibrational coherence. It is shown that the molecular vibrational coherence strongly depends on the effect of coherent population trapping for rotational levels. The obtained results are important for applications of Raman spectroscopy to molecular detection in engineering, chemical, and biological applications.