Fortress Besieged was a classic novel by Qian Zhongshu. The following is an analysis of it sentence by sentence: The meaning of a besieged city was that the people inside the city wanted to go out and the people outside wanted to come in. It depicted the contradiction in people's hearts and the siege effect. In the novel, Fang Hongjian was a man trapped in a besieged city. He tried to escape from the besieged city in various ways, but in the end, he found himself in an even bigger predicament. In the novel, Sun Roujia was a person trapped in a siege. She tried to find her own happiness through the siege of marriage, but in the end, she found that she could only struggle within the siege. In the novel, Tang Xiaofu was a person who yearned for freedom. She tried to escape from the siege but was eventually trapped in the siege for various reasons. In the novel, Zhao Hsin-mei was an observer outside the besieged city. He tried to understand the people inside the besieged city but was eventually trapped by it. The siege effect refers to people always trying to find a completely ideal solution and ignoring the existence of the siege itself. In the novel, Qian Zhongshu was a smart and profound character. Through the image of besieged city, he profoundly revealed the greed, vanity and helplessness in human nature. The siege in the novel is an eternal theme. It reflects the contradictions and difficulties in human society and also inspires us to cherish the life in front of us and not easily fall into the siege.