Suichaozi 隨巢子 "Master Sui Chao", also called Chaozi 巢子, was a Mohist treatise written by Sui Chao 隨巢, a disciple of the famous philosopher Mo Di 墨翟, also known as Mozi 墨子 (c. 476-c. 390 BCE).
According to the imperial bibliography Yiwen zhi 藝文志 in the official dynastic history Hanshu 漢書, the Suichaozi was six chapters long. Tang-period 唐 (618-907) bibliographies speak of a length of 1 juan. The book was already lost during the Song period 宋 (960-1279). It is mentioned in Wei Zhao's 韋昭 (201-273) commentary on the Shiji 史記 and in the chapter Zhuzi 諸子 "Masters" of the literary critique Wenxin diaolong 文心雕龍.
The Qing-period 清 (1644-1911) scholar Sun Yirang 孫怡讓 (1848-1908) in his commentary Mozi xiangu 墨子間詁 ascertains that the content of the Chaozi and the Hufeizi 胡非子, another Mohist treatise, mainly covered the ideas displayed in Mo Di's chapters on the existence of ghosts, against war and universal love.
Ma Guohan 馬國翰 (1794-1857) collected surviving fragments of the Chaozi and published them in his series Yuhan shanfang yiji shu 玉函山房輯佚書.