This paper compares the establishment-level dynamics of the United States and Japan. I find that there are substantial differences in entry and exit behavior, the average employment size of establishments, and the amount of job reallocation. First, entry and exit rates are much lower in Japan. Second, the average size of establishments is much smaller in Japan, while the average sizes of opening/closing establishments are similar in the United States and Japan. Third, the amount of job creation and job destruction is much smaller in Japan, especially for continuing establishments. I first examine whether these differences are accounted for by sectoral compositions, and find that the differences in sectoral composition do not explain these facts. Then I construct a general equilibrium industry dynamics model and explore the roles of various frictions in generating these differences. The model experiments suggest that in Japan there may be important impediments for establishment entry/exit and there may be factors impeding productive establishments from growing larger.