New York-based Open Road Integrated Media says Buck wrote the novel, titled "The Eternal Wonder," shortly before she died in 1973. The publisher says someone found the manuscript in storage in January. It will be published Oct. 22 in paperback and digital formats.
The publisher announced the decision Wednesday, describing the book as the coming-of-age story of a gifted young man whose search for meaning leads him to New York, England, Paris and Korea.
Buck's novel "The Good Earth" won the Pulitzer Prize in 1932 and helped earn her the Nobel Prize for Literature in 1938. She raised seven adopted children and wrote many later works at her farm in suburban Bucks County, where she's buried.