In the last few years, the Brazilian government has been intensifying economic policies of land reform and poverty alleviation. However, the debate about this issue has been overlooking important questions related to the land concentration and the effectiveness of the policy instruments. The aim of the dissertation is to analyze the role of such policies in an environment in which (i) land property provides non-agricultural benefits and (ii) the land rental market does not work well. The results indicate that these two characteristics not only ffect the agricultural efficiency but also the design of development policies. Chapter 1 presents a theoretical model establishing the main framework of the analysis, considering market imperfections and their consequences to the land policies. Chapters 2 to 4 discuss some issues of the implementation of three policy instruments - the land reform program, the land tax and the land rental market. The conclusion summarizes the main results of the dissertation, some limitations and the guidelines for future research.