• Male or female, aged 18 to 70 years (including 18 and 70).

• Voluntarily sign written informed consent.

• Advanced or unresectable soft tissue sarcomas confirmed by pathology mainly include liposarcoma, leiomyosarcoma, synovial sarcoma, undifferentiated pleomorphic sarcoma / malignant fibrous histiocytoma, fibrosarcoma, pleomorphic rhabdomyosarcoma, acinar soft tissue sarcoma, clear cell sarcoma, angiosarcoma, epithelioid sarcoma, malignant peripheral nerve sheath tumor, undifferentiated sarcoma, sarcoma after radiotherapy, etc.

• Patients who have used at least one chemotherapy regimen (including anthracyclines) in the past (except for acinar soft tissue sarcoma and clear cell sarcoma) and are evaluated as disease progression according to the efficacy evaluation criteria of solid tumors within 6 months.

• According to RECIST 1.1, there was at least one measurable tumor lesion.

• ECoG score 0 or 1.

• The expected survival was ≥ 3 months.

• The main organs function well:

• a) Hematology (no blood components and cell growth factors were used to support treatment within 7 days before starting the study treatment):

• i. The absolute value of neutrophils ANC ≥ 1.5 × 109/l (1500/mm3).

• Ii Platelet count ≥ 100 × 109/l (100000/mm3).

• III. hemoglobin ≥ 90 g/l.

• b) Kidney:

• i. Creatinine clearance \* (CrCl) calculated value ≥ 50 ml/min.

• \*The Cockcroft Gault formula will be used to calculate CrCl (Cockcroft Gault formula)

• CrCl (ml/min) = \[(140 - age) × Weight (kg) × F\] / (SCR (mg/dl) × 72)

• Among them, f=1 for men and f=0.85 for women; SCR = serum creatinine.

• Ii Urine protein \< 2+ or 24-hour (H) urine protein quantification \<1.0 G.

• c) Liver:

• i. Total serum bilirubin (TBIL) ≤ 1.5 × ULN.

• II. AST and alt ≤ 2.5 × ULN.

• III. for subjects with liver metastasis, serum total bilirubin (TBIL) ≤ 3 × ULN; ALT and AST ≤ 5 × ULN;

• d) Coagulation function:

• i. International normalized ratio (INR) and activated partial thromboplastin time (APTT) ≤ 1.5 × ULN.

• Female subjects with fertility must have a serum pregnancy test within 3 days before the first medication and the result is negative. If a female issue with fertility has sex with a male partner who has not been sterilized, the subject must take an acceptable contraceptive method since the screening, and must agree to continue using the contraceptive method within 6 months after the last administration of the study drug; Whether to stop contraception after this time point should be discussed with the investigator.

⁃ The subject is willing and able to comply with the visit, treatment plan, laboratory test, and other study requirements as stipulated in the schedule.