What did the early Chinese medical body look like before it was inhabited by the five viscera and before canonical medical rationale was framed in terms of the five agents (wuxing 五行)? This article makes the case for a body with an outwardly visible ‘form’ (xing 形) that housed invisible qi 氣 internally. The qi contained in this body was not the universal qi and all-pervasive stuff that we encounter in later medical texts. Nor can it be limited to the ‘breath’ referred to in the context of meditation techniques, since the term referred also to a moral dimension, thoughts and feelings. In the body's upper spheres, qi took on yang 陽 qualities and was associated with feelings of grief or joy; in its lower ones, it took on yin 陰 qualities and was associated with anger. Since this body was primarily a function of emotional and moral aetiologies, it is in what follows called a ‘sentimental body’, and is contrasted with the canonical ‘body ecologic’ which was most importantly a function of the seasons.The textual material presented in this article suggests that the ‘sentimental body’ with its two yinyang spheres was an early Chinese medical body conception. From an extensive computer search that systematically compared passages on xing and qi in the Yellow Emperor's Inner Canon with texts in the early medical manuscripts from Mawangdui and Zhangjiashan, it emerged as a distinctive body. While the canonical ‘body ecologic’, framed in a pentic numerology, became prominent in medical reasoning during to the Han dynasty (206 B.C.E.–220 C.E.), the ‘sentimental body’, which alludes to yinyang cosmologies, dates to the Warring States period (475–221 B.C.E.).