JICA introduced the guidelines of environmental and social considerations (ESCs) in 2004 and have operated related works for more than 10 years. Quality growth and quality infrastructure are main international agendas and a quality of ESCs is also one part of them. The study aims to propose countermeasures to improve the quality of JICA ESCs, and it reviews and analyzes the quality of JICA ESCs reports, identifies key components to influence the quality, and clarifies a causal relationship between several factors and the quality of reports. The study verifies the causal relationship based on case studies. Eventually the study prepares technical guidelines to improve the quality of reports. The outcomes are expected to improve not only the quality of JICA reports but also the quality of reports prepared in developing countries.