Objective To explore the efficacy of extending the interval of first- time dressing change in such PICC related outcomes as healing rate of puncture site and complications among patients with hematological malignancy. Methods Totally, 117 hematological malignancy patients were randomly assigned to a control group （n=60）, who received first dressing change at 24 h after PICC insertion, and an intervention group （n=57）, who received first dressing change at 48 h.Rates of slight bleeding, infections, and healing at puncture site were compared between the 2 groups. Results The rates of excellent healing at puncture site, and the counts of dressing change had significant differences between the 2 groups （P＜0.01 for both）. Conclusion Extending the interval of first time dressing change to 48 h after PICC insertion could promote wound healing and reduce dressing change frequencies in patients with hematological malignancy.