This paper provides a theoretical framework of how medical help-seeking behavior influences hierarchical medical system. Under the model of free medical help-seeking behavior of heterogeneous patients, there exists structural unbalance of demand in mild disease medical service market and heavy disease medical service market. In the heavy disease service market, mild disease patients crowd out the opportunity of access to medical service. While in the hierarchical medical system, both of the mild disease medical service market and the heavy disease medical service market reach equilibrium, under which circumstances there is no crowding out of medical chance of heavy disease patients. In the hierarchical medical system, we also find that the best geographical location of general hospital is in the center of a city and the best geographical location of basic hospital is in the center of each community