Cáodòng (characters: 曹洞宗; pinyin: cáodòngzōng) is a Chinese Zen Buddhist sect founded by Dongshan Liangjie and his Dharma-heirs in the 9th century. Some attribute the name "Cáodòng" as a union of "Dongshan" and "Caoshan" from one of his Dharma-heirs, Caoshan Benji; however, the "Cao" much more likely came from Cáoxī (曹溪), the "mountain-name" of Huineng, the Sixth Ancestor of Chan, as Caoshan was of little importance unlike his contemporary and fellow Dharma-heir, Yunju Daoying. The sect emphasised sitting meditation, and later "silent illumination" techniques.

In 1227 Dogen Zenji took Caodong to Japan as the Sōtō sect, where it became very popular.

Caodong masters:

• Caoshan Benji (9th century)
• Dongshan Liangjie (9th century)
• Hongzhi Zhengjue (12th century)

See also

• Soto
• Koan