The purpose of the present study was to examine the synchronous relationship between physiological and subjective arousal under an aversive situation. Thirteen subjects received both two conditions, i.e., TUK (time unknown) and TK (time known) ones. Heart rate (HR) was measured as a physiological index, and LDS (Line drawing scale) as a subjective one, in which the subject was asked to express graphically his (or her) subjective tension during the anticipatory period. Main findings were as followes. (1) Main effect of the condition was not observed, but time series changes of HR in the two conditions were different from each other. Heart rate in TK condition tended to increase, while the reverse tendency was found in TUK condition. (2) Changes of subjective tension (LDS) were also observed, of which tendency was similar to that of HR. (3) As the results of cross correlation analysis between HR and LDS, it was shown that changes of HR preceded that of subjective tension. This phenomenon was commonly observed through the conditions, therefore it was suggested that the phase difference between HR and subjective tension was common in anxiety responses.