A system and method is provided for observing a heart rate of a passenger. The system for observing a heart rate of a passenger includes a plurality of different types of heart rate sensors provided on a seat cushion or a seat back, and a control unit for collecting waveforms of the heart rate sensors for respective sensor types, computing accuracies of the waveforms for respective sensor types at each unit time, selecting a waveform having a highest accuracy at each unit time, and then calculating a heart rate.