The challenge faced by newly graduated nurses from undergraduate study to practice is a persistent theme in nursing practice literatures. However, there is a lack of understanding about how this transition happens. This focused ethnographic study explored how newly graduated nurses (novices) interacted with experienced nurses and learnt in a hospital ward in Singapore. Using the 'Trajectory of identification framework' developed from Wenger's Community of Practice theory, data was collected through observation and focused group discussions. This research revealed the participating rules as the sociocultural characteristics of the nursing community, and how these characteristics are ongoingly negotiated among the nurses. The nurses' changing performative competence and identity in different situations are conceptualised as the 'Participation Space'. This study also showed how concepts of Community of Practice theory can be analytically applied and further developed in empirical study. Specifically, a conceptual 'Participation Matrix' is theorised which adds an additional tool to understand the nurses' dynamic participation and negotiation of membership in a Community of Practice. Novices' transition should be viewed as an ongoing dynamic workplace learning, through which negotiation of performative competence and identity among members take place. The soon to be novices and workplaces should be prepared with this understanding.