Based on “Public” and “Information Service” of public library, this article discusses the major concept of marketing is innovation of R&D (Research and Development) for public library. It means the first task for public library marketing is “Product” (quality of public library’s service). This article also brings up the key of the innovation of public library marketing is rather ways of Communication than 4P of Marketing Principles. This is the juncture and possibility of so-called “the innovation of public library marketing”.