The assessment systems for green building have been developed and implemented for decades. Well-known systems include the U.S. system LEED, the U.K. system BREEAM, the Canadian system GB tools, and the Japanese system CASBEE. These systems will be discussed and compared together with Taiwan’s EEWH system. Each assessment system may contain a different set of evaluation items to evaluate the sustainability level of a building project. Contrarily, the assessment system for green civil infrastructure projects is rarely discussed and developed globally. In Taiwan, studies have been conducted to develop a new assessment system with some reasonable key indicators and evaluation items, serving as the tool to evaluate the sustainability level of a green civil infrastructure project. In this paper, the authors studied and summarized different key indicators and evaluation items, and made comparisons among some major assessment systems for both green building and green civil infrastructure projects. Based on the comparison of the various assessment systems, it is found that greenery, recycling of materials, water conservation, carbon emission reduction, and energy saving are considered in both green building and green civil infrastructure assessment systems. Nevertheless, external building structure, energy consumption, healthy air and temperature, illumination of the indoor environment, rainwater recycling, and underground reservoirs are considered only in green building assessments, but not in green civil infrastructure assessments. Moreover, durability, benefits, landscape, humanities, culture, and creativity, which are discussed adequately in green civil infrastructure assessments, are not highlighted in green building assessments. In addition, two construction projects in Taiwan, one green building project and one green civil infrastructure project, are presented to exemplify sustainability practices and assessments.