To evaluate the drug-drug interaction between ZSP1273 and oseltamivir, the pharmacokinetic characteristics and safety of ZSP1273 and oseltamivir in healthy subjects, so as to provide a basis for the design of administration regimen in subsequent clinical trials.

Inclusion Criteria:

• Males and female subjects between 18-45 years (Both inclusive);
• Body weight is no less than 50kg in males and no less than 45kg in females.Body mass index (BMI) 18~26 kg/m2 (Both inclusive); BMI is determined by the following equation: BMI = weight/height2 (kg/m2);
• Subjects (including partners) are willing to voluntarily use effective contraception from screening to 3 months after the last study drug administration.

Exclusion Criteria:

• Known history of allergic constitution (multiple drugs especially with ZSP1273 or oseltamivir and its preparation of the main ingredient allergy, food allergy);
• Subjects who donated blood or bleeding profusely(> 450 mL)in the 3 months preceding study screening;
• History or presence of any disease or condition known to increase the risk of bleeding, eg.hemorrhoids, acute gastritis or gastric and duodenal ulcer, etc;
• Use of any prescription or over-the-counter (OTC) medications, vitamins and herbal within 14 days prior to screening;
• Concomitant therapy with any drugs with known hepatic enzyme-inducing or inhibiting agents that may change the activity of drug metabolic enzymes ，is intended to be taken in combination 28 days prior to screening or during the study period；
• Participated in another clinical research study or received any investigational products within 3 months prior to dosing;
• Presence of clinically significant abnormalities in ECG , QTcB>450ms in males,or QTcB>470ms in females;
• Any of the following diseases (including but not limited to gastrointestinal, renal, liver, neurological, hematological, endocrine, tumor, pulmonary, immune, psychiatric or cardiovascular and cerebrovascular diseases) that are clinically significant in clinical laboratory examination or other clinical findings within 6 months prior to screening;
• Breast-feeding women or those with positive pregnancy test results;
• Subjects who should not be included in the study in the opinion of the Investigator.