three groups; the predominating high urbanization level area, the fast growing and recently high urbanization level areas, and the slow growth areas (Table 2). The first group is Nonthaburi that took advantages of its proximity to Bangkok so that it shared second largest proportion of population growth in peri-urban Bangkok since 1993. Due to the way that more than 50 percent of its population has resided in urban areas from 1993, the province was assessed to be at high level of urbanization from the start. However; as it has been the most densely populated province, the growth of urban population was much slower than other provinces. In the fast growing provinces like Samut Prakan and Pathum Thani, urban population has increased from less than 10 percent in 1993 to over 40 percent in 2002. This is as a consequence of industrial development over the past one and a half decades. They have reached high level of urbanization from 2002. On the other hand, the provinces locating furthest from Bangkok like Samut Sakhon and Nakhon Pathom are the ones that changed slightly as compared to other provinces in the study area. Therefore, in 2007, the two provinces were still at medium-high and medium- low level of urbanization.