《九谷考》是清代学者程瑶田对粱、黍、稷、稻、麦、大豆小豆、麻、苽等九种粮食作物的名实进行深入考证的力作。关于此书的成书年代,近人罗继祖先生认为撰于乾隆三十九年(1774)。本文在对《九谷考》及作者其他著作的研究、分析后,认为《九谷考》完成干乾隆四十五年(1780)至乾隆五十年(1785)间,而不是乾隆三十九年(1774)。 “Nine Valley test” is the Qing Dynasty scholar Cheng Yao Tian on sorghum, millet, millet, rice, wheat, soybean adzuki bean, mahogany and other nine kinds of food crops in-depth textual research masterpiece. About the book’s book age, the recent Mr. Luo Jizu think Qianlong thirty-nine years (1774). After studying and analyzing the “Kutani Test” and other writings of the author, this paper argues that “Kutani Test” completed forty-five years (1780) to Qianlong fifty years (1785) instead of thirty-nine years 1774).