The study of moral conceptual metaphors has been an important topic in recent years. In Chinese culture, the concepts of curvature and straightness are given certain semantic contents, in which curvature refers to being sly while straightness refers to having integrity. In the present study, we used the Implicit Association Test (IAT) paradigm (Experiment 1) and the Stroop paradigm (Experiment 2) to investigate whether there are metaphorical representations of curvature and straightness in moral concepts. The results revealed that the mean reaction time in compatible trials (i.e., moral words accompanied by a straight pattern and immoral words accompanied by a curved pattern) was significantly shorter than that in incompatible trials (i.e., moral words accompanied by a curved pattern and immoral words accompanied by a straight pattern). The Stroop paradigm showed that reaction times were significantly reduced when moral words were presented in a straight font, but there was no significant difference between the presentation of immoral words in a straight font and that in a curved font. The results suggest that mental representations of moral concepts are associated with straightness and curvature in Chinese culture.