Cao Shen 曹參 [not Cao Can!] (died 191 BCE) was a counsellor or emperor Han Gaozu 漢高祖 (r. 206-195 BCE), the founder of the Former Han dynasty 前漢 (206 BC-8 CE). He hailed from the district of Peixian 沛縣 and served as jail warden (yuyuan 獄掾) of the Qin dynasty 秦 (221-206 BC).
In 209 he became follower of Liu Bang 劉邦, the eventual Han Gaozu, in his rebellion against the Qin dynasty. He remained loyal to Liu Bang is his fight against the hegemonial king Xiang Yu 項羽 and served him first as palace receptionist (zhongjuan 中涓), then as left and later as right Counsellor-in-chief (zuo/you chengxiang 左/右丞相).
After the accession of Liu Bang to the imperial throne in 202, Cao Shen was made administrator (xiang 相) of the kingdom of Qi, that was the territory of Han Xin 韓信, and later of Liu Fei 劉肥 (posthumous name Qi Daohuiwang 齊悼惠王), a son of Emperor Gaozu. In 201 Cao Shen was ennobled as Marquis of Pingyang 平陽侯.
Cao Shen remained administrator of Qi after the succession of Emperor Hui 漢惠帝 (r. 195-188 BCE) to the throne. In this position he assembled Daoist scholars (better: adherents of the Huang-Lao school 黃老術) of the region of Qi (modern Shandong) to learn how to exert a benevolent government. He teachings of Master Gai 蓋公, for example, included the art of ruling without action (wuwei 無爲).
In 193 Cao Shen succeeded Xiao He 蕭何 as Counsellor-in-chief of the empire. Continuing with a policy of non-action and did not change or expand the regulations Xiao He had issued. Loyalty was for him a more important character of a state official than the ability to dispute. Cao Shen was known for his love for banquets. When Emperor Hui asked him why he did not exhibit a more active stance in governing the state, Cao Shen answered that Emperor Gaozu and Xiao He had already appeased the empire and settled all affairs. Overhasty activity was, according to Daoist teaching, a characteristic of inappropriate change of the nature of things (the dao) and would only lead to disaster. Legislative activity was contra-natural and would initiate the downfall of a dynasty, as the example of the legalist Qin dynasty had shown. The first decades of the Han dynasty are therefore generally seen as an age of prevalent Daoism. The economical recovering of the country seemed to prove that this kind of policy was correct.
Cao Shen was given the poshumous title of Marquis Yi of Pingyang 平陽懿侯.