The research has as objective to analyze the evolution of the agrarian structure, and the behavior of the economic and social development indicators, for the North and Northwest regions of the Rio de Janeiro state. Moreover, it searchs to verify if the land distribution is an important variable in the explanation of the divergences between the degree of economic development of the cities. The results show that, for the considered regions, the differences in the agrarian structure, separately, can not explain the differences in the degree of economic and social development. The size of the population, in turn, seems to be an important variable in this process. This can be associated to the greater potential demand, what is attractive the private investments. Another reason is, possibly, the greatest politics power, due to the size of the electorate, what can influence in the destination of the public investments.