With college students going into dating relationships, dating partners become their new attachment figures. Attachment anxiety and attachment avoidance are two orthogonal dimensions of adult attachment. Attachment avoidance reflects the degree to which individuals discomfort about intimacy and can make individuals feel that others can’t be trusted and then isolate themselves from others. Attachment anxiety reflects the degree to which individuals worry and ruminate about being rejected or abandoned by their partners and can make individuals feel they can’t deal with distress by themselves and then they rely on others. Both attachment anxiety and attachment avoidance relate to mental health negatively, however, attachment anxiety has stronger association with anxiety and depression than attachment avoidance. Since dating relationship quality is a key factor for mental health among college students, the role of dating relationship quality in the relationship between attachment anxiety and mental health will be investigated in this article. It is hypothesized that dating relationship quality plays both mediating and moderating role between attachment anxiety and mental health. On one side, attachment anxiety is a kind of relatively stable personal traits and attachment style is stable with the change of time. Viewed from this angle, the individuals with high attachment anxiety tend to have a low quality of dating relationship, and then have a low level of mental health. On the other side, the quality of dating relationship is not entirely determined by the level of attachment anxiety. In some cases, dating relationships can buffer the insecurity level and promote the security level of individuals with high attachment anxiety. Viewed from this angle, dating relationship quality can buffer the effects of attachment anxiety on mental health. Based on above hypotheses, the role of dating relationship quality between attachment anxiety and mental health was explored with 595 college students who were in dating relationships currently as subjects. Participants finished the measures including Experiences in Close Relationships Inventory, Mental Health Continuum-Short Form, Center for Epidemiologic Studies Depression Scale-13, and The Relationship Assessment Scale. The results showed that dating relationship quality played both mediating and moderating role between attachment anxiety and mental health. On the one hand, attachment anxiety could have negative influence on mental health through influencing dating relationship quality. On the other hand, high quality of dating relationships could buffer the negative effects of attachment anxiety on mental health. To sum up, the mediating and moderating role of dating relationship quality between attachment anxiety and mental health was confirmed. It can also provide intellectual support for improving the effectiveness of mental health education in colleges and universities. However, some limitations were elicited in this research. Longitudinal data should be used in order to confirm the causal relationship of attachment anxiety, dating relationship quality, and mental health; how the partners perceive the relationship quality should be assessed using both the self-reported and other-report data in the future; attachment anxiety as a state should be taken into account according to the distinction of trait attachment and state attachment.