The purpose of this study is to evaluate the safety, tolerability, pharmacokinetcs and pharmacodynamics of single-dose of JS401 in healthy volunteers with normal or mildly elevated triglycerides.

Inclusion Criteria:

1. Healthy male or female subjects aged 18~60 (inclusive) at the time of signing the ICF, with no less than 1/3 of either gender;
2. Fasting TG≥1.1mmol/L (100 mg/dL) and ≤ 5.0mmol/L (450mg/dL) at screening; (3) Fasting LDL-C at screening> 1.8 mmol/L (70 mg/dL).

Exclusion Criteria:

1. Have a medical history or clinical evidence that the subject has obvious concomitant diseases (including but not limited to: cardiovascular, respiratory, digestive, urinary, neurological, blood, immunological, endocrine and metabolic, infection, etc.), or any clinically significant abnormalities found in physical examination, laboratory examination, and ECG examination, which are judged by the investigator to not meet the standards of clinical health or are not suitable for participating in clinical trials;
2. Acute or chronic infection requiring hospitalization or undergoing systemic parenteral therapy (antiviral/bacterial/fungal/parasitic, etc.) within 60 days prior to randomization;
3. Positive for syphilis antibodies, or positive for human immunodeficiency virus (HIV) antibodies, or positive for hepatitis C virus (HCV) antibodies, or positive for hepatitis B virus surface antigen (HBsAg) at screening;
4. History of substance abuse within 12 months prior to screening, or positive urine drug screening at screening;
5. History of alcohol dependence within 6 months prior to screening, or positive breath test for alcohol at screening