Vigor at work is a positive affection, which is the source of motivation for individuals to work. Improving the vigor of nurses can help increase work engagement, thereby improving the quality of care. There have been many studies on vigor in other occupations abroad, but little is known about how to enhance vigor in clinical nurses, both at home and abroad. Knowing the concept of vigor helps the nursing profession understand where to start to improve the work environment, promote the health of nursing staff, and thus ensure the safety of patients. This article adopts the concept analysis method proposed by Walker and Avant (2019) to establish the defining characteristics of vigor, through listing four cases (typical cases, marginal cases, related cases, and opposite cases) to clarify the concept, confirm the cause and effect of the concept, and propose recommendations from research and clinical practice to improve the vigor of nurses and build a vibrant nursing atmosphere.