Water margin was one of the four famous novels in China and also one of the representative works of ancient Chinese novels. From the Water Margins, one could understand some of the characteristics of ancient novels. The plot of a one-chapter novel is usually composed of a series of chapters, each chapter has its own story and character image, unlike modern novels, which are presented in a continuous form. Each chapter in Water Margins has a different plot and characters, which makes the plot of the novel more compact and allows readers to understand the story more quickly. The narrative style of a two-chapter novel was usually to first summarize the background and theme of the entire story, then unfold the plot of the story one by one. Each chapter would summarize and supplement the previous chapter. In the Water Margins, the author gradually presented the plot of the novel to the readers by describing the scene, portraying the characters, and narrating the plot in each chapter. The characters in the three-chapter novels were usually shaped by describing the appearance, personality, and behavior of the characters. In the Water Margins, the author created many vivid, three-dimensional and profound characters through different character settings and plot designs, so that readers could understand and feel the emotions and humanity in the novel more deeply. The style of a four-chapter novel was usually simple and easy to understand. The words were concise, the plot was compact, and the structure was rigorous. In Water Margins, the author used a lot of spoken language and slang to make the style of the novel closer to life and readers 'reading experience. Water margin is one of the representative works of ancient Chinese chapter novels. From this, we can see that some of the characteristics of ancient chapter novels include compact plots, vivid characters, easy-to-understand writing style and rigorous structure. These characteristics not only made important contributions to the development of ancient novels, but also influenced the development of modern novels.