We utilize information derived from Landsat satellite images to produce eco-environmental vulnerability maps by considering four main factors: hydrometeorology, topography, land resources, and socioeconomics. Twin Taipei Cities are chosen for our study. Their eco-environmental vulnerability assessment (EVA) is first performed. Subsequently, classified regions in needs of environmental protection are proposed. We found that high vulnerable levels are observed in the Taipei Metropolis, consisting of Taipei City and its transboundary regions with New Taipei City as a result of high-density buildings and urbanization with low vegetation. Lowlands in the metropolitan area with concentration of impervious surface might lead to flood if heavy rainfall events occur. In contrast, the regions outside Taipei Metropolis, especially in southwest and southeast parts, have higher quality eco-environment due to better-protected forest areas with lower intervention of human activities. Information of suggested ecological zoning regions is useful for Twin Cities' governments to understand their eco-environmental vulnerability conditions.