Objective To examine the formation elements and influencing factors of quality geriatric care behavior among nursing assistants in nursing homes, and to provide reference for enhancing their geriatric care behavior.Methods Semi-structured in-depth interviews were conducted with 12 nursing managers, 63 nursing assistants and 36 older residents in 9 nursing homes in 6 cities.Data were analyzed using Colaizzi′s seven-step analysis method for phenomenological studies.Results Two themes were summarized:the formation elements of quality geriatric care behavior （personalized, holistic, respect, interaction, empowerment, and maintaining beliefs）; and the influencing factors of quality geriatric care behavior （facilitators and barriers）.Conclusion Eldercare institutions should standardize management, integrate holistic management, strengthen professional training, and motivate nursing assistants′ work enthusiasm, so as to cultivate quality geriatric care behavior.