Family‐related factors are reported to influence the development of postpartum depression (PPD), but limited studies have considered the role of family function in this condition. This study aimed to describe the proportion of people with probable or suspected PPD and to determine the relationships among PPD, family function, and obstetric factors. A cross‐sectional study was conducted with 630 women who attended six integrated teaching and scientific research communities in Changsha, China. Instruments included the Edinburgh Postpartum Depression Scale and the Family Assessment Device (FAD). A multivariate logistic regression model was used to determine the risk factors of PPD. The prevalence of probable or suspected PPD was 37% in this sample. We found communication (odds ratio [OR] = 3.795, 95% confidence interval [CI] = 1.619–8.897), affective responsiveness (OR = 2.685, 95% CI = 1.642–4.301), role (OR = 2.483, 95% CI = 1.041–5.922), and general functioning (OR = 5.704,95% CI = 2.233–14.569) dimensions of FAD, and type of feeding (OR = 2.700, 95% CI = 1.285–5.671) influenced PPD in the context of Chinese culture. To decrease the prevalence of PPD, interventions such as health education programs and cognitive behavior therapy to strengthen family function are recommended among couples during and after pregnancy.