The purpose of this article is to find out the possibility of overcoming the problem of modern philosophy which is represented by the identity philosophy by the problem of 'difference' in Merleau - Ponty 's ‘Body - Flesh Ontology’. In particular, we will note that although Merleau-Ponty's philosophy is still phenomenology, it is distinguished from Husserl's phenomenology and very important. So Merleau-Ponty's phenomenology is the phenomenology of phenomenology and the ‘Body-Flesh Ontology’. Therefore, the problem of 'subject' arises here. Merleau-Ponty finds subjectivity in the body rather than in reason. A body must have individuality, and subjectivity can also be established. The subject can not deny the relationship because it is the subject. The body has identity as a body - subject and communicates with the world. The world is a co-world of body-subjects. Merleau-Ponty therefore explains ontologically the flesh as an ontological foundation upon which body-subjects can have individuality. Flesh is the source of life and fundamental chapter. It is because these bodies are the world bodies that each body can directly contact. Therefore, each body is explained as ‘intercorporéité’, and eventually ‘intercorporéité’ will be confirmed as the foundation of ‘intersubjectivité’. This study suggests that Merleau - Ponty 's body phenomenology and flesh ontology are on a continuous line, and that Merleau - Ponty' s philosophy is ‘Body - Flesh Ontology’.