Inclusion Criteria:

- Patients with tumor pain / postoperative pain, or subjects with pain caused by other
diseases;

- Patients aged ＞30 to ≤ 60 years;

- Body weight ≥ 45kg, and BMI range ≥19, <24;

- Karnofsky score ≥ 70;

- Expected survival is above 3 months;

- The results of liver function and kidney tests must meet the following
criteria:ALT、AST is within the upper limit of normal value ranges by a factor 2, and
TB、BUN、Cr is within the upper limit of normal value ranges by a factor 1.25;

- The electrocardiogram examination results are normal;

- Patients must have given a written informed consent prior to this trial, and have the
capability to complete every required test.

Exclusion Criteria:

- Have hypersensitivity history to any opioids;

- Have known hypersensitivity to any of compositions of the study drugs;

- Patients who are likely to have paralytic ileus or acute abdomen or to perform an
operation on abdominal region；

- Patients with respiratory depression, cor pulmonary, or chronic bronchial asthma;

- Patient unable to stop taking monoamine oxidase inhibitor during this trial period or
time lapses less than 2 weeks since drug withdrawal;

- Patients with hypercarbia;

- Patients with biliary tract diseases, pancreatitis, prostatic hypertrophy, or
corticoadrenal insufficiency;

- Patients with alcoholism or drug abuse history;

- Positive ant-HIV or syphilis antibody test result;

- Urine screening before study is positive for the opioids, barbiturates, amphetamines,
cocaine metabolites, methadone, diazepam and cannabinoids;

- Donated 400 mL or more of blood or blood products within 3 months prior to the start
of the study, or donated 200 mL or more of blood or blood products within one month
prior to the start of the study.

- Subjects who participated in a clinical research study within two months of study
entry.

- Patients who are currently taking opioids.