The aim of this trial is to evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of HRS9531 injection compared with placebo in adolescents with obesity

Inclusion Criteria:

1. Male or female subjects who are aged ≥12 years and <18 years at the time of signing the informed consent;
2. At screening, the BMI meets the obesity criteria according to "WS/T586-2018 Screening Criteria for Overweight and Obesity in School-age Children and Adolescents";
3. Subjects who have maintained a controlled diet and exercise for at least 12 weeks prior to screening, with no more than a 5% decrease in BMI (as reported by the subject, parent, or legal guardian);

Exclusion Criteria:

1. Presence of clinically significant lab results at screening visit;
2. Uncontrollable hypertension;
3. Medical history or illness that affects your weight;
4. History of diabetes;
5. Acute infection, acute trauma, or medium to large surgery within 1 month prior to screening;
6. Confirmed or suspected depression, bipolar disorder, suicidal tendencies, schizophrenia, or other serious mental illness;
7. Use of drugs or treatments that may have caused significant weight gain or loss within the 3 months prior to screening;
8. Pre-adolescent participants (Tanner phase I);
9. Patients with blood donation or blood loss ≥400 mL or receiving blood transfusion within 3 months before screening.
10. Surgery is planned during the tria;
11. Mentally incapacitated or speech-impaired subjects are unable to fully understand or participate in the test process；
12. In the investigator's judgment, there are circumstances that affect subject safety or any other conditions that interfere with the evaluation of the test results.