Being revered as the pioneer of Political Confucianism, or Mainland New Confucianism, Kang Youwei’s theory of Confucianism has received much attention in recent studies of Chinese philosophy. While many studies are devoted to Kang’s theory of Confucianism and his political visions underlying the theory, it is generally overlooked that his arguments are to a large extent built upon his understanding of Mohism. This paper argues that Kang Youwei employs the book Mozi and early narratives about Mozi and Mohism to support his claim that Kongzi was the author of the New Text versions of the classics, that he was an institutional reformer, and also a religious leader. By shedding light on Kang Youwei’s discussion of Mohism, this paper offers a reconstruction of Kang Youwei’s arguments and a different angle for investigating the origin of Political Confucianism.