We studied the vibrational coherences during the ultrafast internal conversions (ICs) of pyrimidine nucleobases and -sides in aqueous solutions and the gas phase with an instrumental resolution of 14 fs. The coherence of the same ring-breathing vibrational mode with a frequency of 750 cm-1 was observed. In the gas phase, the vibrational coherence was transferred during IC from the 1ππ* to the 1nπ* state, and it survived for approximately 1 ps. In an aqueous solution, the vibrational dynamics develop in the 1ππ* state because the 1nπ* state is energetically upshifted via hydrogen bonding with H2O, and the vibrational coherence is lost on a similar time scale as that of IC to the ground electronic state.