OBJECTIVE: To investigate the drug use in oncology department in Chongming Branch of Xinhua Hospital（ hereinafter referred to as “our Hospital”）

so as to provide reference for improving the rational drug use in clinic. METHODS: According to the Pharmaceutical Care Network Europe（ PCNE） classification system

the irrational use of drugs in 2 392 medical records of oncology department in our hospital in 2020 was analyzed. RESULTS: In2020

there were 2 392 medical records discharged from oncology department

of which 348 medical records had drug related problem（ DRP）

accounting for 14. 55%. A total of 392 case-times of DRP occurred

and with reference to the PCNE classification system

the number and percentage of DRP for Treatment Effectiveness

Treatment Safety and Other Aspects were 92 case-times（ 23. 47%）

146 case-times（ 37. 24%） and 154 case-times（ 39. 29%）

respectively. In terms of the causes of DRP

the number of case-times and the percentage of causes for “drug selection”（ 253 case-times

64. 54%） took the lead

followed by “dose selection”（ 87 case-times

22. 19%）. From Jan. to Dec. 2020

the incidence of DRP in oncology department of our hospital showed the decreasing trend.CONCLUSIONS: Through the analysis and summary of PCNE classification

it is found that there are certain problems in drug use in oncology department of our hospital

and clinical pharmacists still need to strengthen the review and intervention of anti-tumor drugs to promote the rational drug use.