Urbanization is the rise of population in the urban areas. Recently, an increasing number of people have migrated from rural to urban areas, which has accelerated the process of urbanization. This upward trend is not restricted to developing countries but also developed countries. According to Tyler Miller and Spoolman (2008), the driving force of urbanization lies in social, economic or even religious reasons, which means people move to cities for a better quality of life. However, along with urbanization benefits, problems of urbanization appear. As a result, these problems will pose a threat to both residents’ living condition and natural environment. To solve these problems, the governments and urban planners believe that sustainable development is an efficient way to achieve. Sustainable development means that people should search to enhance their living condition without damaging the natural environment (Adams 1999). In this essay, it will give an overview of the urbanization problems in two aspects, which are insufficient urban space such as housing shortage and environment destruction as well as urban transportation problems such as traffic congestion and air pollution. After that, this essay will discuss the problems of urbanization can be partly addressed by the sustainable solutions due to some limitations. The first problem connected to urbanization is that there is not enough urban space for the growing population, particularly in developing countries. Firstly, some studies have pointed out that houses in cities are in great demand, which leads to housing shortage. This is because the population grows not only in the nature ways associated with the increasing birth rates and decreasing death rates, but also in the way that a large migration of people move from rural to urban areas for more desirable life (Tyler Miller & Spoolman 2008; Bilham-Boult et al. 1999). Additionally, as stated by Tyler Miller and Spoolman (2008), poverty is an existing life style for many urban inhabitants in most of the developing countries because a great proportion of them are unemployed. The authors go on to say that the only places they can afford to live are the slums and squatter settlements where there are few clean water supplies, low coverage of sewage systems and lack of legal electricity. For example, in Mexico City, more than 33 per cent of the poor dwellers have built inadequate, prohibited shanty towns from waste materials such as plastic sheets and scrap wood, which are without basic services and fringed around the city (Tyler Miller & Spoolman 2008; Bilham-Boult et al. 1999). Similar situation also has happened in developed cities, such as Hong Kong. Since about 1947, squatter settlements have appeared only in the mainland and the island at first, yet it has spread to the colony and the New Territories due to the continual arrival of refugees from China and Vietnam (Chaffey 1994). This then leads to serious overcrowding and lack of normal facilities which may cause negative consequences for environment. Secondly, lack of urban space has also caused damages to the environment. First of all, with the expansion of urban population, a large amount of trees and shrubs, which have positive effects on environment, such as giving off oxygen, absorbing carbon dioxide and cooling the air, are cut down for more room to build houses and roads (Tyler Miller & Spoolman 2008). Moreover, houses are even built on the farmlands in Mexico City (Bilham-Boult et al. 1999). Once these places are damaged, it may be ruined forever or it may take years to recover. Second, many authors agree that the contamination in poor urban areas including both water and land pollution that results from inadequate water supplies, sanitation, drainage, and waste collection is considered to be the most direct environmental problem of cities in the developing world (Tyler Miller & Spoolman 2008; Bilham-Boult et al. 1999; Elliot 1999). As it can be seen