From a time-based to a competency-based medical education, the evolution of residency training began nearly 30 years ago, the development of valid and reproducible assessment tools faces challenges.Medical educators across specialties remain motivated to develop a relevant, generalizable, and measurable system.The Accreditation Council for Graduate Medical Education (ACGME) in the United States commits to the responsibility by assuring that the process and outcome of graduate medical education (GME) in the national residency programs produce competent, safe, and compassionate doctors.The Milestones Project is the ACGME′s evolution to a competency-based system, which allows each specialty to develop its own subcompetencies and 5-level progression of Milestones, along a continuum of novice to expert.Milestones 1.0 provided important foundational information and insights for the education community, that has had nearly 5 years of experience for residency training in Anesthesiology, needs to be improved.Milestones 1.0 highlighted challenges with assessment and evaluation of residents, some mismatch between subcompetencies and current and future clinical practices in Anesthesiology, and the need for faculty development tools.The ACGME assembled representatives from stakeholder groups using an iterative process within the Anesthesiology community to develop the second generation of Milestones in 2021.This article describes Milestones 2.0 for residency training in Anesthesiology in the United States, emphasizing the rationality and practicability, to provide evidence for residency training in Anesthesiology in China.There is a lack of systematic, cooperative and continuous research on medical education in Anesthesiology in China, and a lack of competency-based and milestone-based residency training in Anesthesiology.It is urgent to narrow the gap between developed countries and China to improve medical education and training in Anesthesiology.