Unjust development has not necessarily expanded the spatial size of urban economy in competitive market. The land as a factor of production have only selected a land use with the highest productivity. However, when a market failure occurs, the invisible hand, which guides the conversion of land to urban use, pushes too hard in the direction of bigger cities. The methods of settlement to these problems in economics are to use the price mechanism, which is extremely traditional. In this article I discuss the following three questions:(1)Why have economic activity leaded to urban sprawl? (2)Is it judged as excess from what standard it is if it is the one that making excessive suburban sprawl in the present? (3)What market intervention it justify against to excessive suburban sprawl?