A Japanese version of the Sensation-Seeking Scale was developed based on Zuckerman's SSS Form IV. Items of Zuckerman's Form IV were translated into Japanese and were administered to Japanese undergraduates (458 males and 431 females). The results were factor-analysed to select items for the scales. Four factors were originally postulated, but the results were more easily interpretable when five factors were extracted, especially in the female sample. This fifth factor was regarding marihuana use and sexual behavior. In order to match the structure of the scales for both males and females, items highly loaded with this factor were eliminated and the results for the remaining items were again factor-analysed. Then the following four scales were constructed; Thrill and Adventure Seeking (TAS), Experience Seeking (ES), Disinhibition (Dis), and Boredom Susceptibility (BS). Items of TAS scale were highly consistent with Zuckerman's TAS items of Form V. But items of ES, Dis and BS scales were different from those of Zuckerman's and the scales turned out to be those uniquely constructed from Form IV. The test-retest reliabilities (test-retest interval was three months) of the total SSS were .87 and .73 in males and females, respectively. TAS, ES and Dis reliabilities were ranging from .74 to .86 for males, and .74 to .82 for females. However, males' and females' BS were less reliable (.54 and .48 respectively). Internal consistency reliabilities (KR-20) of the total SSS were .75 for males and .65 for females. TAS, ES and Dis reliabilities were ranging from .56 to .67 for males, and .47 to .61 for females. But the BS scale showed poor reliability (.29 for both males and females).