Purpose: Chinese kindergarten teachers commonly held "loving and caring for young children" as a core professional ethic, but many reported fatigue and burnout because of this ethical practice. This study presents a unique account of how children's free play has helped transform teachers' professional ethics and increased their professional satisfaction. Design/Approach/Methods: Following a purposive sampling, we interviewed eight Chinese teachers who actively promoted children's free play. The analysis of the interview transcripts led to an in-depth interpretation of the teachers' experiences through a dialogue with various concepts and theories. Findings: A major finding was that children's free play facilitated the change in teachers' understandings of their professional ethics. Their observation and support of children's free play brought them the unprecedented joy of teaching, which helped them redefine loving and caring for children and gave rise to a new code of professional ethics. Originality/Value: This study was the first to assess the Chinese kindergarten teachers' ethics in the free play movement in China. It reveals, in the teachers' own words, how their growing commitment to supporting children's free play has transformed their beliefs and understandings of what a loving and caring teacher means.