• The patient shall sign the Informed Consent Form.

• Aged 18 ≥ years.

• Histological or cytological diagnosis of SCLC by needle biopsy, and limited stage (local advanced) confirmed by imageological examinations.

• Eastern Cooperative Oncology Group (ECOG) performance-status score of 0 or 1.

• Life expectancy is at least 12 weeks.

• At least 1 measurable lesion according to RECIST 1.1.

• Patients with good function of other main organs (liver, kidney, blood system, etc.):

‣ ANC count ≥1.5×10\^9/L, platelet count ≥100×10\^9/L#hemoglobin

‣ ≥90 g/L;

⁃ the international standard ratio of prothrombin time (INR) and prothrombin time (PT) \< 1.5 times of upper limit of normal (ULN);

⁃ partial thromboplastin time (APTT) ≤1.5×ULN;

⁃ total bilirubin ≤1.5×ULN;

⁃ alanine aminotransferase (ALT) aspartate aminotransferase (AST) ≤2.5×ULN, or ALT and AST ≤5×ULN in the patients with liver metastatic tumor.

• No systemic metastasis;

• Expected to be completely resected;

⁃ Good cardiopulmonary function and can tolerate surgical treatment;

⁃ Fertile female patients must voluntarily use effective contraceptives not less than 120 days after chemotherapy or the last dose of Tislelizumab (whichever is later) during the study period, and urine or serum pregnancy test results within 7 days prior to enrollment are negative.

⁃ Unsterilized male patients must voluntarily use effective contraception during the study period not less than 120 days after chemotherapy or the last dose of Tislelizumab (whichever is later).