In parliamentary democracies, governments are formed through parliamentary elections, and both the cabinet and budget must receive the confidence of the legislature. The "golden age", when parliaments make laws without any pressure from the executives and have strong control over cabinets, ended by 20 th century. For the last few decades, however, legislative studies have been pointing to a shift in the balance of power from the legislative to the executive branch in many countries. The declining power of parliaments is explained by many factors. Scholars who studied "declining parliaments" generally agree on the commonly accepted contributing factors for deparliamentarization. These factors are "constitutional arrangements, increasing global regulations, the complexity of issues and technicalfocus in policy making, disciplinary party structures, the lack of intra-party democracy, the domination of parties by their leaders, and electoral systems. " Although a trend of deparliamentarization has been noted, mainly in parliamentary democracies, the decline of parliaments has not been as glaring and forbidding everywhere. Thus, the variation, especially among similar democratic systems, calls for a closer analysis of country cases. This study examines Turkey, and discusses the changes regarding the power balance between the executive and legislative branches of government by identifying the pattern of changes in constitutions and country's electoral system, and party structures which tend to stress party discipline and maintain leaders' control. The paper analyzes the politics of Turkey between 1946 and 2014 especially by focusing on the AKP rule after 2002. The power shift in Turkey has been from parliamentary supremacy to a very strong executive, and deparliamentarization has been particularly rapid and profound since the 1980s,. In 2017, a change in the constitution allowed a transition to a presidential system and the new system is legalized by the constitutional amendments. The paper concludes with the analysis that there is a significant decline in the power of the parliament in Turkey, after 1980s, mainly in its scrutiny function. The longitudinal study of changes shows that deparliamentarization, or the increase in the power of the executive, was caused by multiple domestic and international factors that occurred simultaneously and reinforced each other's impact. The significant difference of Turkey from the other world cases are rapid constitutional changes, increasing leader authority within the parties, and existence of dominant party system in Turkey since 15 years.