From Zhiyuan to Qisong, a chain of Hanyu criticism also seen in the scholar official stratum presents itself among the Buddhism circle in the Northern Song Dynasty. These two people adopt entirely different attitudes towards Hanyu's achievements in ancient prose and his philosophical thoughts. One totally affirms them while the other denies them. There are three factors attribute to this situation, namely, different era conflicts, different critical targets and also different critical focus. However, behind these two seemingly different attitudes, the common ideological essence can be found. The essence consists of four aspects, firstly, Hanyu's identity as an "ancient prose expert"; secondly, Confucianism of critical criteria; thirdly, the deep motivation of protecting Buddhism; and lastly, the academic thought of combination of Confucianism and Buddhism. This Hanyu criticism is of great significance in culture. On Buddhism, it marks the convert in development of Buddhism in the Northern Song Dynasty. On literature, it signifies the opening of "ancient prose movement", which promotes the prosperity of "ancient prose writing". On Confucianism, it establishes the Neo-Confucianists' keynote of Hanyu criticism, and also opens up the new academic path of "illustrating Confucianism through adoption the doctrine of Buddhism".