Objective To explore the effect of caring diary applied in ICU patients. Methods ICU patients admitted in 2018 were divided into a control group of 318 and an intervention group of 403 chronologically, receiving either routine care or additional caring diary intervention focusing on humanistic caring ,with the caring diary being modified from ICU diary.The incidence rates of anxiety and depression within 24 hours of ICU admission and at transferring out of ICU were compared between the two groups, and patient and family satisfaction with the implementation of caring diary in the intervention group was collected. Results The incidence rates of anxiety and depression in the intervention group were significantly lower than those in the control group at transferring out of ICU （P＜0.05,P＜0.01）.Patient and family satisfaction score was 8.75±0.56. Conclusion Writing caring diary in ICU can help critically ill patients and their families reduce the incidence of anxiety and depression and improve their satisfaction with critical care.