The EU has revealed its more conclusive energy policy following its Green Paper of 2006. The new policy integrates the climate change and energy, which was adopted at the European Council of March 2007. Recently, the EU also emphasizes the importance of the external policy within the energy policy, which is based on a concept of the energy security with diversification of energy sources, supply countries and supply routes. Against such a European framework, this paper will examine the prospect of Turkey's accession from the perspective of security of supply of natural gas. Turkey finds itself located in between a major production area and a large consumption area of natural gas: the Caspian region and the EU. With such a privileged geopolitical location, Turkey aims at becoming an energy hub, not a mere transit country, for the natural gas as well as for the oil. Among the numerous pipelines Turkey facilitates, there stretch two BTC pipelines starting at Baku, Azerbaijan finishing at Çeyhan, Turkey, without passing through the Russia territory. Turkey waits for the construction of the NABUCCO project to start in 2010, which is to pump the gas from the Caspian region directly to Europe without touching the Russian soil. Russia is the main provider of natural gas both for the EU and Turkey. As the gas stoppage in January 2009 demonstrated, it is recognized as an urgent task specially for Europe to obtain alternative routes of gas supply. For this end, Turkey is geopolitically advantageous over Europe. However, with delays in liberalizing the Turkish internal energy market and the still uncertain situation of NABUCCO, Turkey does not seem to hold strong cards for its accession negotiation with the EU. The Energy acqui has not been opened yet, either. The EU opts for its usual ambiguous attitude toward Turkey while emphasizing the importance of Turkey as a strategic partner but leaving Turkey as the only non-EU state among the 6(six) NABUCCO contractors.