While China&rsquo / s economic development has made tremendous progress, it has also caused serious environmental pollution problems. This paper uses the date of the Chinese Private Enterprise Survey (CPES) to empirically investigate the impact of Confucianism on corporate environmental investment and its internal mechanism. The results show that: (1) Confucianism plays a significant role in corporate environmental investment. (2) In the areas where environmental regulation is relatively weak, Confucianism has a more significant effect on promoting corporate environmental investment. (3) The positive influence of Confucianism on corporate environmental investment is more obvious in heavy polluting industries. This paper&rsquo / s conclusions deepen the theoretical cognition of the economic consequences of Confucianism and enrich the relevant literature on the subject of Confucianism. At the same time, this paper also expands the understanding of the determinants of corporate environmental investment from the perspective of the informal institution.