Regional ecology, as one of important subjects in ecology subject systems, originates from the regional comprehensive scientific survey and regional environmental pollution investigation. The primary objectives of regional ecology are devoted to study the background of regional environmental issues, their driving forces, and further seeking solutions to the existing environmental issues. However, the basic theory and methodology of regional ecology is still in development because of the complex research objects and the complex issues faced. In this paper, the characteristics and subject orientation of regional ecology was discussed based on previous studies and literature review. The differences between regional ecology and the other subjects such as landscape ecology, ecosystem ecology, regional physical geography, macro-ecology was compared. (1) The study object of regional ecology is the specific complex eco-region that was usually dominated by some specific issues. Such a specific complex eco-region has both spatial homogeneity from the predominant factor and spatial heterogeneity from the coupling effects of multiple factors. (2) Regional ecology is devoted to solve the regional environmental issues, thus it requires to have a logic mind of multiple-integration, issue-driving and systemic integration, and further to find the solutions to the regional environmental issues from multiple view-points and hierarchical thinking. (3) Regional ecology is in the higher position in ecology subject systems, i.e., from molecular ecology, individual ecology, population ecology, community ecology, ecosystem ecology, landscape ecology, regional ecology and global ecology.