To Assess the Effects of Single Dose of JMKX001899 on QTc Interval in Healthy Subjects

Inclusion Criteria: 1. Healthy, adult, male or female 18-45 years of age, inclusive. 2. Body mass index (BMI) between 19 and 28 kg/m2 (inclusive) and weight at least 50 kg. 3. Participant must sign an informed consent form (ICF) indicating that he or she understands the purpose of, and procedures required for, the study and is willing to participate in the study. Exclusion Criteria: 1. Patients with a history of clinically significant diseases including, but not limited to, gastrointestinal, renal, liver, neurological, hematological, endocrine, neoplastic, pulmonary, immune, psychiatric, or cardiovascular and cerebrovascular diseases, epilepsy, bipolar disorder/mania, intraocular hypertension, or acute angle-closure glaucoma. 2. Female subjects with a positive pregnancy test or lactating. 3. Positive results at screening for human immunodeficiency virus (HIV), hepatitis B surface antigen (HBsAg), hepatitis C virus (HCV) or Treponema pallidum（TP-Ab）