This paper is an attempt to expound and clarify the main points of Dewey’s naturalistic metaphysics. Section one deals with Dewey’s definition of metaphysics as a study of the generic traits of existence and takes issue with Hook`s and Rorty’s negative view concerning Dewey’s enterprise. Section two deals with Dewey’s empirical method, in which such key concepts as “primary experience” and “selective emphasis” are examined. Section three deals with Dewey’s substantive metaphysical theories, using his treatment of the mind-body problem as a typical example. Section four deals with four generic traits of nature found or implied in Dewey’s metaphysical works: change, quality, interaction and continuity. Section five defends Dewey’s position against some criticisms raised by Santayana, Cohen and others, while at the same time points out that Dewey’s concept of “primary experience” is ambiguous and that his purely functional approach to natural existences is one-sided.