Urban expansion in the vertical dimension affects the atmospheric transmission and energy balance at both local and city scales, and thus alters urban thermal environment such as intensifying the urban heat island effect. Understanding how three-dimensional morphology affects urban climate dynamics is crucial for urban sustainable development and managing our landscapes. This paper presents a comprehensive review on how urban three-dimensional morphology affects land surface and air temperatures in urban areas. We first reviewed the current states and trends in quantification of urban 3D morphology, with a particular emphasis on previous studies that focused on the effects of urban 3D morphology on urban thermal environments. We then summarized how urban 3D morphology affects land surface and air temperatures in urban areas by reviewing existing studies. We found that sky view factor (SVF) and street height/wide ratio (H/W) were the two most frequently used, and important 3D morphological indicators that significantly impact thermal environments. Based on the review of the existing studies, we suggested a few future directions:1) choosing and/or developing 3D indicators that can more comprehensively reflect the true 3D morphology of urban areas, and more planning and designing relevant. For example, 3D indicators shall consider the effects of trees, rather than buildings and roads alone. Additionally, when choosing or developing indicators, their relevance to urban planning and design shall be considered. 2) Future research shall be more focused on the mechanism on how urban 3D morphology affects urban thermal environments, as existing studies mostly focused on the statistical relationship between them. 3) Cross-city comparisons are highly desirable.