AbstrakMembandingkan sistem pemerintahan presidensiil di Indonesia dalam sistem hukum civil law dengan sistem presidensiil Amerika Serikat (AS) dalam sistem hukum common law, dapat dipahami perkembangan karakteristik sistem ketatanegaraan masing-masing negara. Mengikuti perkembangan pemikiran founding fathers tentang dasar negara, mereka menyatakan pembentukan negara Republik Indonesia didasarkan atas corak hidup bangsa Indonesia yaitu sistem kekeluargaan dan akan menggunakan sistem pemerintahan yang sesuai dengan corak masyarakatnya. Akan tetapi dengan adanya reformasi pada tahun 1998, penegasan sistem pemerintahan presidensiil disepakati dalam agenda sidang MPR yang membahas tentang perubahan UUD 1945. Dalam pelaksanaan sistem presidensiil di Indonesia yang tumbuh dalam sistem civil law terdapat juga pengaruh common law. Dibuktikan dengan dianutnya prinsip-prinsip parlementarian. Ada upaya purifikasi sistem presidensiil, akan tetapi menjadi perlu pembenahan terutama pada infrastruktur politik dan penataan beberapa Undang-Undang (UU) di bidang politik. Sedangkan sistem pemerintahan presidensiil Amerika Serikat sudah menyatu dalam praktek ketatanegaraannya, karena Amerika Serikat merupakan tanah kelahiran sistem presidensiil dan merupakan contoh ideal karena memenuhi hampir semua kriteria yang ada dalam sistem pemerintahan presidensiil. Ada beberapa kelebihan dan kekurangan di masing-masing sistem pemerintahan presidensiil antara Indonesia dengan Amerika Serikat. Hal ini disebabkan beberapa pengaruh  yang mendukung efektifitas pelaksanaan sistem tersebut antara lain tentang sistem hukum yang mendasarinya, sistem kepartaian, sistem politik dan perkembangan demokrasi yang mewarnai pelaksanaan sistem ketatanegaraannya. Kata kunci: Perbandingan, Sistem Pemerintahan, Common Law, Civil Law, Sistem Pemerintahan Presidensiil AbstractComparing the presidential government system in Indonesia under civil law system with a presidential system of the United States (US) under a common law system, it can be understood from the development of the characteristics of the constitutional system of each country. Following the development of the basic ideas of the founding fathers of the state, they declared the establishment of the Republic of Indonesia based on the style of life of the Indonesian nation that kinship system and will use a system of government in accordance with a pattern of society. However, with the reform in 1998, assertion of presidential government system was agreed on the agenda of the Assembly session that discusses the changes in the Constitution of 1945. In the implementation of the presidential system in Indonesia is growing in the civil law system there is also the influence of the common law. It is proved by the principles espoused of the parliament. There are efforts to purify the presidential system, but it becomes necessary infrastructure improvements, especially in the political and structuring some Act (Act) in politics. While the US system of presidential government are united in the practice of political subdivision, because the United States is the birthplace of the presidential system and is an ideal figure since it meets almost all the criteria that exist in the system of presidential government. There are some advantages and disadvantages of each system of presidential government between Indonesia and the United States. This is due to several influences that support the effective implementation of the system, among others, about the underlying legal system, party system, political system and democratic development that characterizes the implementation of the system of political subdivisions. Keywords: Comparison, System Administration, Common Law, Civil Law, Presidential Government SystemÂ