The purpose of this study is to identify the specific causes of problems in the derelict space underneath overpasses and to create improvement strategies based on systems thinking from a long-term CPTED perspective. The research questions are as follows: 1) Which feedback relation does the structure between crime occurrence frequency and crime anxiety in derelict spaces underneath overpasses? 2) Which CPTED strategies can control the strategic points of derelict spaces underneath overpasses? Results of the study are as follows. First, “community cohesion in the life zone” was selected as strategic points. Second, to control the strategic points, “plant design”and “lighting design” were suggested for “Natural surveillance”. These CPTED strategies increase opportunities for “natural surveillance”and may prevent a public space. This study is a significant step towards understanding the causes of derelict spaces from a systems perspective. The results of this study indicate basic design guidelines for modifying the long-term use of derelict spaces underneath overpasses into more desirable public spaces.