To evaluate the effect of Jaktinib Hydrochloride Tablets on QT/QTc interval in healthy subjects after a single oral administration.

Inclusion Criteria:

• Voluntarily sign informed consent, able to comply with the requirements of the study.
• Age 18-45 years old, both male and female;
• Weight: male ≥ 50 kg, female ≥ 45 kg, 19 kg/m^2 ≤ BMI ≤26 kg/m^2.
• 12-lead electrocardiogram (ECG) examination, 300 ms≤QTcF<450 ms, 120 ms≤PR interval ≤200 ms, and QRS duration <120 ms;
• The subjects (including male subjects) are willing to voluntarily take effective contraceptive measures within the next 3 months.

Exclusion Criteria:

• Have a history of risk factors for torsade de pointes, or have a family history of short QT syndrome, long QT syndrome, unexplained sudden death in young adulthood (≤40 years old), drowning or sudden infant death syndrome in first-degree relatives;
• Previous history of hyperkalemia, hypokalemia, hypermagnesemia, hypomagnesemia, hypercalcemia or hypocalcemia;
• Subjects who had donated blood or lost ≥400 mL of blood within 3 months before screening;
• HBsAg, HCV antibody, HIV antibody, or TP antibody antibody positive.
• Women with positive blood pregnancy test (applicable to women) or lactating women;
• Subjects who have other factors that the investigator considers unsuitable for participation in the study.