In Japan, although oral oxycodone is widely used for cancer pain treatment, there is no injection preparation of oxycodone used as a single ingredient. Only the compound injection of oxycodone and hydrocotarnine has received approval. Subcutaneous administration of the drug is approved, but there are few efficacy and safety reports about its intravenous administration. We compared 245 patients(187 intravenous administration patients and, 58 subcutaneous administration patients)to whom the compound injection of oxycodone and hydrocotarnine was administered from April, 2008 to September, 2011, in order to investigate the drug's efficacy and safety. The reasons for injection were the impossibility of oral administration in 105 patients, a need for dose adjustment in 56 patients, and that other drugs were not as effective in 37 patients, and side effect reduction in 33 patients. The average change in the numeric rating scale(0-10)was 3. 7→1. 8 in intravenous administration, and 3. 4→1. 2 in subcutaneous administration. The incidence of main adverse events(intravenous administration/subcutaneous administration)were constipation(37%/28%), vomiting(31%/34%), and somnolence(52%/50%). There was no significant difference in efficacy and safety. The conversion ratio differed in a case due to a change, and about 20 to 40% of addition was needed within four days after the start. It is considered that compound injection of oxycodone and hydrocotarnine is effective for cancer pain treatment.