This study employed the principle of national sovereignty, democratic participation, and freedom of the information as its overarching theory, and utilized the methodology of a case study method. By analyzing the London Assembly, this study suggests that the idea of parliamentary transparency includes disclosing legislative procedures and promoting the personal integrity of councilors'. It was found that the best approach to establish parliamentary transparency is to facilitate more than the freedom of the information. In addition to the approach of the freedom of the information, the transparency of parliament could be promoted by engaging more citizens to involve parliamentary agendas in terms of the experience of the London Assembly. In addition, the parliamentary transparency can bring the parliament more power to oversee executive administration.