We perform ultrafast transient absorption spectroscopy of oxy-hemoglobin by a pump-probe method with ultrashort laser pulses. Negative time-range of the observed traces, where the pump pulse precedes the probe pulse, is analyzed to study the electronic coherence dynamics between the excited state and the ground state, and the vibrational coherence in the electronic excited state. The analysis result shows that the electronic coherence between the electronic ground state and the Q-band state dephases in 45+(-)5 fs. The vibrational dephasing times of modes with frequencies of 210, 393, 554, 731, and 1106 cm?1 are found to be 449, 366, 555, 1085, and >1330 fs, respectively.