⁃ Patients must meet all of the following inclusion criteria to be enrolled in the study:

⁃ 1\. Patients voluntarily participate in the study and sign the informed consent form; 2. Age ≥ 18 years and ≤ 75 years; 3. Have pathologically confirmed gastric adenocarcinoma or gastroesophageal junction adenocarcinoma; 4. Patients with gastric or gastroesophageal junction adenocarcinoma at the clinical staging of cT3-4 or N+, M0 (staging according to AJCC version 8) who could be radically resected as determined by CT and laparoscopy; 5. Have not received anti-tumor therapy (such as surgery, radiotherapy, chemotherapy, targeted therapy, immunotherapy, etc.); 6. Planned surgical treatment after completion of neoadjuvant therapy; 7. Able to swallow tablets normally; 8. ECOG score 0-1; 9. Expected survival \>=12 months; 10. Main organ functions normal, i.e., meeting the criteria below:

• Blood routine examination criteria shall meet:

• (No blood transfusion or blood products within 14 days, no G-CSF or other hematopoietic stimulating factors are used for correction) Absolute neutrophil count ≥1.5×109/L; Platelet ≥80×109/L; Hemoglobin ≥ 80 g/L

• Criteria for biochemical tests:

⁃ Total bilirubin \<1.5×ULN; ALT and AST≤2.5×ULN;

⁃ Serum Cr ≤ 1.5 × ULN or endogenous creatinine clearance \> 50 ml/min (males: Endogenous creatinine clearance rate = ((140-age) × body weight)/(72 × serum Cr); female: endogenous creatinine clearance rate = ((140-age) × body weight)/(72 × serum Cr) × 0.85; body weight unit: kg; serum Cr unit: mg/mL):

⁃ 11\. Female subjects of childbearing potential must have a negative serum pregnancy test within 7 days prior to the first dose and be willing to use a highly effective method of contraception during the trial and for 120 days after the last dose. Male subjects with partners of childbearing potential should be surgically sterilized or agree to use highly effective methods of contraception during the trial and for 120 days after the last dose;