An extensive molecular equilibrium calculation has been performed under sunspot conditions in order to resolve the current dispute on the presence of C 2 lines in the spectrum of sunspots. Equilibrium abundance of C 2 has been computed under the conditions of umbral cores, umbrae and the normal photosphere. As the results, it is found that the umbral cores yield unfavorable environment for C 2 formation. It is concluded that C 2 molecular lines are not likely tn be observed in the spectrum of sunspots.