In this research, five German taste adjectives süß, sauer, bitter, salzig, and scharf, are analyzed in terms of their original meanings and metaphorical usages. Based on Lakoff’s theory of metaphor and example analysis, it is found that: 1) German adjectives of taste have the semantic characteristics of taste directionality, quality, subjectivity, standard reference, and relativity in their original meaning; 2) When used as metaphors, taste adjectives show four characteristics except taste directivity, and a new characteristic of emotion is added. Moreover, metaphorical adjectives of taste can be collocated with specific verbs to express human emotions and psychological states according to their emotional characteristics.