This study is aimed to study the pharmacokinetic characteristics(e.g. AUC, Cmax, Tmax) of Ypeginterferon alfa-2a and interferon biomarkers(e.g. 2,5-OAS, neopterin) after single dose at different levels.

Inclusion Criteria:

• Healthy subjects
• Age between 18 and 45, inclusive
• Body mass index(BMI)between 19 and 26, inclusive
• Sign informed consent

Exclusion Criteria:

• Women of pregnant or lactation
• Known hypersensitivity to interferon or any other components of the study drug
• History of mental disease or genetic disease
• History of diabetes mellitus, thyroid disease, cancer, autoimmune disease, organ transplant
• Significant disease in heart, liver, kidney, lung or any other major organs
• Alcoholic, smokers or drug abusers
• Blood donation, or massive blood loss due to injury or surgery within 3 months
• Other conditions which in the opinion of the investigator preclude enrollment into the study