A so-called global city that plays an important role in regional and global economic, political and cultural development should perform well in terms of its livability. The livability level of Beijing was compared with those of three acknowledged global cities, i.e., New York City, Greater London, and Tokyo-to to clarify whether Beijing has great potential to grow into a global city. From the aspects of social development, living standard and environmental quality, the livable level integrated index (LLII) was established in this paper to evaluate the urban livability, while the linear weighted sum was applied as the assessment model. After analyzing the situations of the four cities during 2000–2009, it was indicated that the LLIIs of Beijing, New York City, Greater London, and Tokyo-to were respectively 38.76, 52.93, 50.95, and 40.65 in 2000. By comparison, the LLIIs in 2009 were 38.96, 59.23, 69.24 and 52.15, respectively. Further analysis showed that a big gap exists between the environmental quality of Beijing and those of three global cities and the performance of social development for Beijing declined in the last decade. To accelerate the transformation of Beijing to a global city, much more attention should be paid to improve the environmental quality, especially the atmospheric quality and water quality.