Japan’s publishing market is comprised of the paper printing market and the digital publishing market. The electronic publishing company can be divided into electronic magazines, electronic comic books, and words-based e-books. Compared to the paper printing market, which underwent more than twenty years’ downturn, the digital publishing market has been growing steadily. Besides the attribution of the widespread use of portable electronic communication devices, the promotion and execution of various e-books-related services also contributed to the apparent growth of e-books. E-book market has also expanded gradually. During this time, I’ve come to develop a deep interest in the e-book free-reading service. The subject of my research is Japan’s digital publishing market. The objective is to study the development of e-book’s service and its effects. First, I extracted research data regarding the publishing market published by出版科学研究所 and Impress 綜合研究所. Next, I analyzed the current situations of the paper printing market, digital publishing market and the entire publishing market respectively. Despite continuously growing annually, the scale of the digital publishing market is still unable to stop the shrinking of the publishing market as a whole. The scale of the digital publishing market is different from the paper printing market, which is gradually decaying. Second, the next chapter looks back on the history of e-books, exploring the birth of e-books to the formation of digital publishing market. Since the era of stand-alone games which was without the internet, e-books has undergone various forms. Now, the most popular forms of e-books are in smartphones and laptops. Next, I analyzed the expansion of the digital publishing market in chronological order, and probed into the services of e-books in different times. In addition, the electronic magazine market was able to revive because the digital publishing market had introduced the e-book free-reading service, which has drawn a lot of attention in recent years. Although the current electronic comic book market is mainly about free comic books applications and single-book purchases, the e-book free-reading service has also gained support from a different group of readers. As of words-based e-books, even though the current market scale is smaller and mainly took form in single-book purchases, with the widespread of future electronic digitization, words-based e-books still have a lot of room for growth. Lastly, I made a prediction regarding the future trend of the market based on my research above. Since the expansion of the current digital publishing market cannot compensate for the shrinking of the paper publishing market, the market scale of Japan’s publishing market will continue to shrink. Despite this, due to the expansion of various digital publishing services including e-book free-reading service, electronic digitalization will continue to prevail, and the digital publishing market will continue to grow. How will it continue to grow? And will it have a chance to catch up to the scale of the paper publishing market? The development of the digital publishing market is worthy of our attention.