This paper seeks to respond to this major question that if Iran accedes to the World Trade Organization (WTO) and observes copyrights, in the realm of intellectual property, what demand and supply changes would occur in Iran’s book market. To respond the above question first some instances of breaching the copyrights in book publishing sector is investigated. Then calculating the price and income elasticity, the impact of observing the copyrights on price and income, and therefore on the demand and supply for books in short term is demonstrated. The findings of this research reveal that with accession of Iran to WTO and observation of copyright, some of the subsidies to the book sector must be terminated, and also the non-national authors would receive royalties. With elimination of subsidies and payment of royalties book price will increase by an average of 7.5 percent and demand would decrease by 13.35 percent. But, supply will show less sensitivity and its increase in short term would be insignificant. Yet, as experienced in other countries, for numerous reasons such as entering the international markets and increased quality, the printing volume of books will increase. In long term, the experiences of other countries have shown the same trend.