The physical development of the Jakarta Metropolitan Area (JMA) and the Bandung Metropolitan Area (BMA) is characterized by the formation of an urban belt from Jakarta to Bandung of about 200 km, reflecting a growing mega-urban region marked by a mixture of rural and urban activities and blurred rural-urban distinction. This process is continuing at an even with faster rate than in the period from the 1980s to the mid-1990s. In fact, the JMA and the BMA are both experiencing transformation from singlecore to multi-core cities. In the past three decades the development of socioeconomic activities has resulted in several environmental problems. The JBR also faces problems of uncontrolled land conversion. New town developments have reinforced spatial segregation by life style and income status while industrial estates are also growing in the region. There is a tendency of local governments in the JBR to try to exploit local resources excessively. The JBR is a functional region that should be managed as an inseparable region through an integrated spatial development plan. Institutional development is now critical to ensure the sustainability of the JBR.