Buck claimed that after completing The Good Earth "I found my mind so filled and absorbed with Wang Lung's family that I felt quite compelled to go on with them.

As time passes, Wang the Landlord is forced to sell much of his share of the land in order to support his family's lavish lifestyle, with the Merchant buying the best tracts for himself.

The Tiger also captures a hostile young woman who had been the Leopard's consort and imprisons her for a time, then releases her after putting an end to the corruption in the magistrate's courts.

The Tiger begins to introduce him to military life with the goal of eventually putting him in command of the army, but the boy shows more interest in farming as Wang Lung did.

At this time, Wang Lung's mentally disabled daughter (the “Poor Fool”) dies, further fueling the Tiger's son's interest in the land on which she had lived.

The rift between the two grows when the boy turns fifteen and his father sends him to a military school; four years later, the Tiger is shocked to see him wearing the uniform of an army that is fighting a revolution against the government and the warlords.

Salt Lake City Tribune reviewer E. E. Hollis states the theme of Sons to be "how with these great families, risen from the soil, the process of decay set in within an early generation.

"[2] Birmingham News reviewer Dorothy Herzfeld felt the main theme to be "that when the farmer leaves his true habitat, the soil, he degrades himself morally and spiritually.

[5] Courier-Journal critic Anna Blanche McGill described it as a "good, if not magical piece of workmanship" that does a "studious, painstaking job of observing and recording, if not a masterpiece of creative imagination.