The present invention provides a psychosomatic state determination system 1 for the purpose of predicting or determining the psychosomatic state of a subject without imparting any awareness to the subject, comprising a data processing means 20 for calculating a psychosomatic state exponent such as Lyapunov exponent from the time series signal of a load value or a barycentric position of the subject, and an evaluation means 22 for comparing the temporal tendency of a psychosomatic state exponent calculated in said data processing means with the temporal tendency of a known psychosomatic state exponent corresponding to a psychosomatic state to thereby predict the psychosomatic state of the subject.
