A national museum traditionally represents one kind of culture of a nation. When a national museum is founded, does it become an achievement of a political leader or a democratic institution belonging to the public? This research aims to compare the definition of national museums in different countries, then to understand their development in and influences upon the society. Based on the re-branding strategies of national museums in the UK, it is obvious that these cultural institutions are heavily influenced by the cultural devolution during the last two decades. Another significant change in the UK is that most national museums has established partnership with other museums, instead of setting up more branch museums, which is another political influence. On the other hand, the national museums in Taiwan has been developed and affected by government policies for a long time, and gradually they have turned to take more accountability in contrast to less resources. The lack of efficient resources and the change of operations are the major effects on these cultural institutions and these impacts could paralize the institutions accordingly. It is hoped that this paper will give Taiwan government some ideas to figure out a better way to get the balance of allocating resources and accountability to national museums. The future of national museums is expected to expand their characteristics and to make better performances in leading the cultural sector.