Inclusion Criteria:  Subjects must meet all of the following inclusion criteria to be eligible for participation in this study: Healthy male or female subjects between 18 and 45 years old; Body weight more than 50.0kg (male) or 45.0kg (female), body mass index (BMI) within the range of 19.0~26.0kg/m2 (both inclusive); Subjects and their partners should have no fertility plan, no sperm or ootid donation plan and must use highly effective contraceptive methods (such as abstinence, condom, etc.) from the screening period to 6 months post-trial; Additional inclusion criteria apply;  Exclusion Criteria:  A subject will not be eligible for inclusion in this study if any of the following criteria apply: Clinically significant abnormalities in baseline results of laboratory evaluations; Subjects has a positive result of any of following virology tests (hepatitis B surface antigen HBsAg, hepatitis B core antibody HBcAb, hepatitis C virus HCV antibody, human immunodeficiency virus HIV antibody, Treponema pallidum antibody TP-Ab) ; History or evidence of clinically significant cardiovascular, pulmonary, endocrine, gastrointestinal, psychiatric, neurologic, hematological or metabolic diseases, especially those conditions that interfere with absorption, metabolism and/or excretion of the study drug, determined by the investigator; Any previous or current severe infection, such as cellulitis, pneumonia, sepsis etc., requiring hospitalization and/or intravenous antibiotic treatment, within 30 prior to the screening period; Have participated in clinical trials of other drugs or medical devices within 3 months or within 5 half-lives of other drugs before screening (if 5 half-lives exceed 3 months); History or presence of allergy, especially known allergy to investigational product components or other JAK inhibitors; Had taken any medication, including prescription, over-the-counter, herbal, dietary supplements, or vaccines, within the previous 2 weeks; or within the five half-lives of the aforementioned drugs prior to randomization;