Objectives: This study aimed to examine the mediating effect of coping strategies on the relationship between family functioning and posttraumatic growth in family caregivers of people with dementia (PwD). Methods: A total of 124 family caregivers of PwD from a memory clinic were investigated from July to October 2017. Family functioning, coping strategies, and posttraumatic growth of family caregivers of PwD were measured. Data were processed using descriptive statistics, correlation analysis, regression analysis, and structural equation modelling. Posttraumatic growth was observed in family caregivers of PwD. Results: The caregiver's gender, relationship with the patient, and difficulty balancing financial income and expenditures in the past month, as well as disease severity of PwD, are significant predictors of posttraumatic growth. There were significantly positive correlations among posttraumatic growth, family functioning and positive coping strategies (P＜0.01). Positive coping strategies exert a complete mediating effect between family functioning and posttraumatic growth (β = 0.49, P < 0.05). Conclusions: A model of the posttraumatic growth of family caregivers of PwD can be established, and the relevant mechanisms can be explored. Healthcare providers should pay attention to the family functioning of caregivers and take effective measures to provide them with positive coping strategies to promote their posttraumatic growth.