Aim: To compare the effect of family integrated care (FICare) on maternal stress in preterm infants with traditional non-parent neonatal intensive care unit (NICU) care. Methods: We continuously enrolled mothers and their preterm infants from two NICUs between August 2014 and April 2017; while one NICU applied the FICare model (FICare group) and the other performed standard non-parent care model (control group). Maternal stress was evaluated by the Parental Stress Scale: NICU (PSS: NICU) on admission and right before the discharge. A generalized linear model to adjust for potential confounders. Subgroup analysis was also performed for comparisons between two groups.Results: A total of 215 mothers with preterm infants were included in this study, among whom 118 (54.88%) were in FICare group and 97 (45.12%) were in control group. The mean PSS: NICU score was 117.36 ± 26.27 on admission with no difference between two groups. Before being discharged home, the PSS: NICU score of parents in both groups was significantly reduced, with the score of FICare group was significantly lower than that of control group. In all sub-domains of PSS: NICU score as sights and sounds, baby looks and behavior score, and parental role, the scores of FICare group were significantly lower than control group.Conclusions: There was a simultaneous decrease of maternal stress for NICU preterm infants. FICare further facilitates reducing the maternal stress. It shall be encouraged to apply FICare model in NICUs.