This book relates events in the last year of the life of Ah Q, a village idler and odd-jobber in the Chinese village of Weichuang.
The unnamed narrator gives the reader a satirical first-person perspective on the shortcomings of the Chinese national character as mirrored in Ah Q and his fellow
villagers. The story also provides a commentary on the state of the revolution which had occurred in 1911 and had supposedly done away with the feudal elements of society.
After confessing himself to be unable to ascertain Ah Q’s surname, personal name (thus he is called Ah Q in lieu of a correct name), or place of origin, the narrator gives a series of vignettes showing Ah Q and his relations with his fellow villagers. It is immediately apparent that Ah Q lives in a world of self-deception. He frequently gets into quarrels with village idlers and is invariably bested by them, the disputes ending with Ah Q having his head knocked against a wall five or six times. He additionally obliges his enemies by calling himself an insect and a beast. Ah Q nevertheless manages to rationalize these defeats into victories by claiming moral or psychological superiority over his opponents.
His relations with the more influential villagers are no more amicable. Mr. Chao, whose son has just taken his bachelor’s degree, despises Ah Q as a no-good and slaps his face upon learning that Ah Q has been bragging that he is related to the Chao clan. Ah Q himself hates the "Imitation Foreign Devil," a student who has just returned from Japan and wears foreign dress. Apparently, Ah Q is even more disturbed by the fact that this person is wearing a false pigtail than he is about the young man’s selling out to foreign ways.
One day, Ah Q encounters a young Buddhist nun in the street and proceeds to tease her unmercifully, pinching her cheek and taunting her about monk-nun relationships. This draws laughs from onlookers but also precipitates feelings in Ah Q about sex which eventually impel him to make an indecent proposal to Amah Wu, the servant of Mr. Chao. Amah Wu, a chaste widow, is completely flustered, and Mr. Chao severely punishes Ah Q and has him pay damages. The consequence is that women now avoid him, the wine shop refuses him credit, and no one will hire him. Hungry, he wanders out of the village and eventually arrives at the Buddhist convent, where he steals turnips from the garden. He is chased away by an old nun and a ferocious black dog. At this point, Ah Q decides to leave the village and go to the city.
Several months later, Ah Q returns to the village, now with adequate money, boasting of having seen
revolutionaries executed in the city. His status rises in the eyes of the villagers, and he starts selling the numerous items that he has brought back with him. Even his relationship with the more affluent villagers is changed for the better. Mr. Chao, lusting after bargains, sets aside his dislike for Ah Q and proposes to buy the goods that Ah Q has. Mr. Chao does this even though he suspects that they are stolen items and cautions his wife to keep the doors and windows locked. Later, when it is learned that Ah Q did indeed gain his money and possessions through thievery, his status is lowered again in the eyes of the villagers, especially since he is merely a petty thief and receiver of stolen goods and not a daring robber.
As word reaches the Weichuang villagers that revolutionaries have indeed entered the city, the narrative picks up its pace. Mr. Chao and his son become fearful and start currying favor with the Imitation Foreign Devil, who has joined the revolutionary party. Ah Q decides that the revolution must be a good thing, since Mr. Chao is afraid of it; indeed, Ah Q wants to become a revolutionary himself, but he is not asked to join the "revolutionary activities," such as robbing Mr. Chao’s house and ransacking the convent.
At this point, Ah Q is suddenly arrested by the revolutionaries as a suspected accomplice of the splinter group which robbed Mr. Chao. Ah Q is as uncomprehending as ever and continues his self-deception and rationalization by assuming that it is the fate of everyone to be arrested at some time. Finally, as he is brought to the execution ground, he becomes dimly aware of what is happening and perceives the nature of the crowd, which is unfeeling and clamoring for a good show.