To evaluate the safety, tolerability and pharmacokinetic characteristics of HSK39004 dry powder inhalation in healthy subjects.

Inclusion Criteria:

1. Voluntarily sign the informed consent form, understand the trialprocedures, and be willing to comply with all trial procedures andrestrictions;
2. 18 years to 45 years (inclusive), male and female;
3. Male subjects weight ≥50 kg and female subjects weight ≥45 kg. Body mass index (BMI) : 18-26 kg/m2 (inclusive) ;
4. Normal lung function during the screening period, no airway obstruction, FEV1 and forced vital capacity(FVC) are at least 80% of the predicted values;
5. Never smoked or have quit smoking for ≥ 12 months and have a previous smoking history of < 5 pack per years;
6. Subjects are willing to voluntarily use effectivecontraceptives from screening to at least 3 months after the last dose administration.

Exclusion Criteria:

1. Have a history of severe and uncontrolled diseases, such ascardiovascular, respiratory, liver, gastrointestinal, endocrine,hematologic, mental/nervous systems diseases within 3 months prior to screening;
2. Have a history of any malignant tumors;
3. Normal or abnormal vital signs, physical examination, laboratory examination, electrocardiogram, and imageological examination have no clinical significance;
4. Previous or current gastrointestinal, liver, kidney, or other disease known to interfere with drug absorption, distribution, metabolism, or excretion;
5. Acute respiratory infections occurred within 6 weeks before screening and/or before randomization;
6. Have a history of high consumption of grapefruit juice, methylxanthinerich food or beverage within 48 hours before the administration;
7. Average alcohol intake is more than 14 unit per week (1unit=10g alcohol , 1 unit=285 mL 4.9% alcohol beer, or 30 mL 40% alcohol spirit, or 100mL 12% alcohol wine) within the 3 months prior to screening;
8. Have a history of drug abuse prior to screening, or positive urine drug screen at screening;
9. Blood donation (or blood loss) ≥400 mL within 3 months prior to the screening;
10. Subjects who have a allergic to any component of HSK39004 or allergic history;
11. Subjects who use any live vaccine within 30 days prior to screening;
12. Have participated in any clinical investigator within 3 months prior to screening;
13. A pregnant/lactating woman, or has a positive pregnancy test at screening or during the trial;
14. Not suitable for this study as judged by the investigator.