The purpose of this study was to evaluate the effect of various flavoured jellies on the palatability and bitterness of the Kampo medicine 'Orengedokuto', using human gustatory sensation testing. In the gustatory sensation test, eight items were evaluated according to the semantic differential (SD) method and four taste intensities (sweetness, astringency, sourness, and bitterness) were determined. Factor analysis of the results identified two main factors 'Disagreeable taste' and 'Agreeable taste and odour' as predominantly determining the palatability of Orengedokuto. To investigate the influence of jelly odour, evoked images were obtained for five fundamental tastes after smelling jellies. The inhibitory effect of the jelly odour on the bitterness of Orengedokuto was found to be small. When the influence of the various jellies on the disagreeable taste of Orengedokuto was investigated, the bitterness intensities of Orengedokuto mixed with chocolate or strawberry-chocolate jelly were found to be significantly lower than the bitterness of the control. The bitterness intensity of Orengedokuto was found to be significantly and negatively correlated with sweetness intensity using simple linear regression analysis. These results suggest that the sweetness intensity of various jellies inhibits the bitterness intensity of Orengedokuto.