Discourses on orthodoxy in the Northern Song Dynasty were based on the ＂cycle of the Five Elements＂, or whether a character succeeded or failed in certain events. At that time, the orthodoxy of Cao-Wei was widely discussed. Ever since Zhu Xi views that Shu, instead of Wei, was the orthodox legacy of Han dynasty, and his praising of Liu Bei and reproaching of Cao Cao had become the mainstream ideology, these two historical figures had always been interrelated in many various discourses. This study explores whether such orthodoxy concepts affected the literati's comments about Cao Cao. Through reviewing and analyzing historical texts, this study identifies that literati did not oppose or even recognize the Cao-Wei orthodoxy due to political reasons or because they had to acknowledge ＂factual achievement＂ as historians. However, due to the rising of Confucianism once again in the Northern Song Dynasty, ＂ethics＂ became a crucial element on how the literati viewed history, although it was not highlighted in most discourses on orthodoxy. In this case, poems served as a vehicle in which scholars and intellectuals could express their emotions. These poems provided an alternative viewpoint on the Three Kingdom Dynasty from the literati’s perspective, which was excluded from the orthodox history. In these poems, the image of Cao Cao had been villainized because of his immoral actions, including his injudicious execution of talented intellectuals and disloyalty towards the Han regime. They did not portray the heroic side of him as compared to works written in the Tang Dynasty, and the poems written after the mid Northern Song Dynasty further portrayed him as being resented by both God and men. Therefore, Cao Cao was not positioned as a noble character in the Northern Song Dynasty, although the literati affirmed that the Wei Dynasty was a legitimate bearer of the Mandate of Heaven. These views promoted the gradual defiling of Cao Cao's image since the Tang Dynasty to the Southern Song Dynasty.