Objective To investigate the effect of exercise diary on arm exercise compliance ofpatients with peripherally inserted centralcatheter (PICC). Methods Thirty patients with PICC hospitalized in our hospital from June to August in 2017 were selected as the control group, where the patients received guidance on functional exercises through arm exercise videos and routine methods. Another thirty-two patients hospitalized in our hospital from September to November of 2017 were selected as the observation group, where in addition to the same treatment as in the control group and these patients received interventions using their self-designed exercise diary for a total of 31 days. Their compliance with functional exercises before and after intervention and the incidences of venous thrombosis after intervention were compared between the two groups. Results After interventions, the compliance rate of arm exercises in the observation group was significantly higher than that of the control group (90.6% vs. 26.7%, P＜0.05). The incidence of venous thrombosis in the observation group was significantly lower than that of the control group (3.1% vs. 30.0% , P＜0.05). Conclusions Exercise diary can improve the arm exercise compliance of PICC patients and prevent the occurrence of venous thrombosis. It is worthy of clinical application and promotion.