Abstract: Humans as social beings cannot live without linguistic understanding， which is the guarantee of the being of human beings in the world. Both late Wittgenstein and Gadamer expound as to why it is possible for humans to achieve linguistic understanding， namely， the former is from the epistemological dimension while the latter from the ontological dimension. Comparatively， Wittgenstein presents us linguistic understanding in the sense of the epistemology of language in terms of context and language in use， while Gadamer's philosophical hermeneutics presents us an ontological understanding of linguistic understanding taking the time axis as the focus to demonstrate linguistic understanding as an ontological being due to the disclosure of humans' being in the world. The good acts as the ethical leverage to ensure linguistic understanding， which is true both in Wittgenstein's and Gadamer's linguistic understanding.

Key words: linguistic understanding, epistemology, ontology, dimension, the good