Having the characteristics of public goods, Radio Spectrum had been controlled by Government Authorities. In the past, technological side of spectrum, such as cross protection, was the main concern, but as the telecommunication industry is developing gradually, economic side of spectrum is becoming an important part. To uplift the Economic efficiency of spectrum management policy, clarifying the basic value of spectrum is one of the most important things. Also, both government authorities and spectrum licensees will have to choose license or investment under uncertainties such as license timing, time to market, technology standard, and so on. Considering all things, this paper gives the value to the spectrum by real options theory, which is a powerful method concerning uncertainty, especially for government, And we applied it to a specific spectrum band for the portable Internet in Korea. These results can provide information about the technological standard, optimal market-entry time as well as the value of spectrum for the portable Internet.