The human watching moving images displayed on a wide-field display or screen sometimes suffers from the visually-induced motion sickness (VIMS) that induces symptoms related to the autonomie nervous system such as nausea, vomiting, and dizziness. The previous study indicated that the maximum cross-correlation coefficient (ρmax) between blood pressure and heart rate whose frequency components are limited to the neighborhood of 0.1Hz is a useful index to evaluate the effects of the VIMS on humans . The present study has proposed a new method for obtaining ρmax with measurement of neither continuous blood pressure nor ECG but using only finger photoplethysmography. The adequacy of the proposed method was evaluated on the basis of comparison with the conventional method. An experiment in which multiple subjects were simultaneously watching the same swaying video image was carried out. The experimental result has shown that the proposed method worked successfully as well as the conventional method.