In the development of virtual communities, a new phenomenon of virtual money is observed and presented high importance to both e-commerce and e-society fields. This paper, as a pioneer research, has attempted to make a phenomenal analysis on the existing virtual money systems. By the analysis, this paper has defined what virtual money is, what its general models are, and how its existing systems work. By the analysis, the features of existing virtual money systems are abstracted and their problems are summarized. Driven by the motivation of utilizing and improving the existing virtual money systems, this paper has outlined a novel generic virtual money system model called Common Money (CONEY) to resolve the problems that bother the existing virtual money systems. Finally, further interesting issues for future research are given. © 2008 IEEE.