This paper addresses a puzzle with regard to the question of the concept of body in the thought of aesthetics of Merleau Ponty, which is not noticed by us. According to Merleau Ponty, the concept of body is a kind of field('champ' in french), which is also the beginning of his thought of aesthetics. In fact, by regarding the body as a field ('champ' in french), he combined the ontology of aesthetics with its epistemology, opened the dimension between individuality and ego, even between the others and history. So this paper attempt to demonstrate why the body as a field becomes the beginning of Merleau-Ponty's thought of aesthetics, and how it becomes the thread of his thought of aesthetics.