半總統制的運作特色是行政權力分別由總統和總理掌握，當半總統制的總統權力較小，就會由總理主導行政權力，此時半總統制的運作模式趨近於內閣制。但過去較少有文獻比較總統權力較小的半總統制國家，與內閣制國家的實際政治運作，是否有顯著的差異。本文先參照Wu(2012)的分類，選擇準內閣制做為總統權力較小的半總統制次類型，再與內閣制國家做比較。 本文的研究結果，發現準內閣制與內閣制之間，在國會的有效政黨數目、無黨籍總理出現的機率、總統總理同黨的機率沒有顯著的差異。顯示準內閣制的總統如同Wu分類的定義，不會介入任命過程，另外，總統選舉的衣尾效應也無法使大黨的席次增加。在總理任期的比較方面，雖然兩種制度的總理任期沒有顯著的差異，不過準內閣制的總理遭遇提前選舉下台的風險，低於內閣制，且準內閣制的總理連任機率也低於內閣制。這些結果皆表示，準內閣制的總統雖然不會介入組閣過程，但有可能對於國會的選舉時程產生影響，使總理無法在最佳時機發動國會提前選舉，進一步降低總理的連任機率。 綜合本文的研究發現，再對照過去的相關理論。半總統制與內閣制在實際運作上，仍然有一些差異。近年來，學界認為總統權力不是半總統制的重要條件，實際上，即使在總統權力較小的國家，總統權力可能還是有重要的影響。 / The executive power in semi-presidentialism is shared by the president and prime minister where the prime minister will control executive power with a weak president, and the political practice will be like those found in parlimentarism. There are very few articles examining the difference between parlimentarism and semi-presidentialism with a weak president. This paper compares the political practice of semi-presidentialism with a weak president and parlimentarism in different countries. The case selection criteria of a weak president is based on Wu(2012). In his research, quasi-parlimentarism is a subtype of semi-presidentialism, that the president has weak power. The result of this research demonstrates that effective number of parties in parliamentary, probability of non-party prime minister, president and prime minister in the same party have no significant difference between two institutions. This means that in the quasi-parlimentarism the coattail effect of a presidential election does not ensure more seats for a large party, and the president has a weak power to appoint the cabinet. Although the duration of the term of a prime minister has no significant difference, the hazard of early election, and probability of prime minister renewal in quasi-parlimentarism is less than parlimentarism. This means that a president in quasi-parlimentarism has blocked dissolution of parliamentary, and the prime minister cannot call for an early election at his or her favorable time. In summary, the political practice of semi-presidentialism is different than parlimentarism. Presidential power is an important feature of semi-presidentialism, even in small presidential power, a semi-presidentialism country, and its president have great influence on politics.