Previous studies reported our perceived taste may be altered by our affective states. The aim of this study was to examine the effects of affective states introspection on taste perception. Eighty-three healthy Japanese participated in this study. All participants watched two types of 15-minute videos that evoked relaxation and anxiety. After watching each video, half of the participants were manipulated to introspect on their affective states by answering an anxiety questionnaire after viewing each video. The other half of the participants were asked to answer a personality test and introspect their personality traits. After completing each questionnaire, participants rated the intensity of sweetness, saltiness, sourness, bitterness, and liking of the taste stimulus by using Visual Analog Scale. Considering the possibility of different perceptual changes depending on the type of taste stimulus, half of the participants in each introspection group rated unsweetened coffee and the other half rated sweetened coffee as a taste stimulus. Analysis was conducted by a generalized linear mixed model with affect (relaxed/anxiety), target of introspection (affective state/personality trait), taste stimulus (unsweetened/sweetened) as fixed effects, and participant and taste stimuli as random effects. The results showed that anxiety significantly enhanced bitterness only in the group that introspected their own anxiety. In addition, we found that anxiety significantly suppressed sweetness and sourness, regardless of the presence or absence of affective states introspection. These results indicate that there are two types of effects of anxiety on taste perception, depending on the taste quality. One type of taste quality changes in perceived intensity with or without introspection, and the other type changes only with introspection. The effect of the affective state on the perception of taste quality may depend on the biological significance of the change in it.