Land and housing is one of the basic needs of cities habitants. The price increase in this market have caused to increase problems for the citizens. Land and housing problems is affected by different elements and each of these elements has the main role in its changes. Among these elements, the increase in inflation, price of building materials, costs of labour force, to be near to the populated and economic center and etc. These elements are the most effective in changes of land and housing market. But in Iran cities and in particular in city of Zanjan, the main factor (element) have unstabled the land and housing market is the role of unofficial land market, which has been more effective than inflation rate in recent years. This article will study the different factors (elements) effecting in land and housing market in Zanjan by using the available documents, libriries and field study with regard to unofficial land market. Since city of Zanjan is being located near to the capital city (Tehran), consider as important reason of land and housing problems.