Environmental conservation planning as set forth in the "Framework Act for Environmental Policy" is a representative planning that demands linkages with spatial development planning like urban master plan. However, despite the intentions and efforts of government (including revision of relevant guidelines etc.), controversy still continues regarding the efficacy of environmental conservation planning in respect of its linkages to spatial development planning. Accordingly, this study was devised to examine existing issues and produce proposals for improvement in ensuring the efficacy of environmental conservation planning by local governments. This study focused in particular on the establishment of spatial environmental plans as suggested in the guidelines of the Ministry of Environment for the purposes of strengthening the efficacy of environmental conservation planning. Based of questionnaires for relevant officials of local governments, the study found that although local governments with established current spatial environmental plans are not numerous, the need for establishment of spatial environmental plans were high in terms of the applicability of environmental conservation and spatial plans. Furthermore, this study also confirmed through analysis of questionnaires data, archival research and case study research that there were a number of salient issues including an overly access and program centered planning method based on individual pollution sources and individual post factor measures in the planning aspect, a lack of usable spatial information in the application of spatial environmental information, and inadequate connections with spatial development planning in respect of linkages with other plans. Under these circumstances, various proposals for improvement were presented including the establishment of contents in environmental conservation planning for each urban master planning item from the standpoint of planning, strengthening of basic environmental surveys for spatial planning and preparation of applicable proposals from the perspective of leveraging of spatial environmental information, and systematic improvements that can enable mutual consideration through feedback between environmental conservation planning and urban master planning from the perspective of connections with spatial planning.