Among the Four Great Masterpieces, only 'Dream of the Red Chamber' was the most controversial because of the following reasons: 1. Literature value: Dream of the Red Chamber is regarded as the pinnacle of Chinese classical novels, and its literary value has always been controversial. Some people think that it is a classic of ancient Chinese novels, with extremely high literary value and rich cultural content, while others think that it is a serious plagiarism of foreign novels, with limited literary value. 2. Historical background: The background of Dream of the Red Chamber was the feudal society of the Qing Dynasty. The deep exposure and reflection of social reality such as family, marriage, and officialdom, as well as the deep discussion of human nature, led to extensive discussions and disputes about feudal society and human nature. 3. Character image: The characters in Dream of the Red Chamber are vivid, the plot is complicated, and the character is deeply shaped and three-dimensional. Some people think that the characters are too full, and some characters 'behaviors and motives lack reasonable explanations. Others think that the character description is very realistic, and it is one of the best character descriptions in ancient Chinese novels. 4. Cultural background: The cultural background depicted in Dream of the Red Chamber is also one of the reasons why it is controversial. Some people thought that it reflected the deep problems and contradictions of the feudal society of the Qing Dynasty, while others thought that the cultural background depicted in it was too feudal and conservative, which was quite different from the values of modern society. In summary, the literary value, historical background, character image, and cultural background of Dream of the Red Chamber were all controversial. Different people had different attitudes and views towards it.