Inclusion Criteria:  Patients with willingness to be in the study and follow all study procedures, and capable of providing informed consent Male or female aged 18-70 years; Patients with unresectable, locally advanced or metastatic relapse/refractory sarcomas that have failed at least the front line standard treatment confirmed by histology or cytology; At least one measurable lesion, i.e. the length of non-lymph node lesions examined according to CT cross-sectional scanning or magnetic resonance imaging (MRI), or the short diameter of the lymph node lesions is ≥15 mm according to RECIST 1.1, and the FDG PET signal from the measurable lesion is > 3 SUV; Tumors with AXL positive (IHC 1+ or greater) in ≥50% of all tumor cells. A new biopsy is required if the sample is over one year. ECOG Performance Status 0-1; Expected survival greater than 12 weeks;  Adequate organ and hematopoietic system functions to meet the following requirements:  Hemoglobin (HGB) s 90 g/L, no blood transfusions within two weeks; White blood cell (WBC) count≥2.5×109/L； Absolute Neutrophil Count (ANC) ≥1.5×109/L; Platelet (PLT) count ≥80×109/L; Total bilirubin (TBIL) ≤3.0ng/dL or ≤5 ULN; ALT and AST ≤5 ULN; for liver metastasis, ALT and AST ≤5 ULN Creatinine (Cr) ≤1.5 x ULN; or creatinine removal rate (CrCl) ≥50 mL/min; PT: INR < 1.7 or extended PT to normal value < 4s Normal language, recognition and consciousness assessed by investigator during screening phase; Capable of receiving treatment and follow-up, including treatment in the clinical center;  Exclusion Criteria:  Females with pregnancy or in lactation period; Subjects with active hepatitis B, or active hepatitis C. Subjects with undetectable HBV DNA or HCV RNA after anti-virus treatment can be enrolled; HIV positive; Other active infections of clinical significance;  Subjects with the following previous or accompanying diseases:  • Subjects diagnosed as severe autoimmune diseases that require long term (more than 2 months) treatment with systemic immunosuppressants (steroids), or diseases with immune-mediated symptoms, including ulcerative colitis, Crohn's disease, rheumatoid arthritis, systemic lupus erythematosus (SLE), and autoimmune vasculitis (e.g. Wegena granuloma);  Patients with previous diagnosis as motor neuron disease caused by autoimmunity; Patients previously suffered from toxic epidermal necrolysis (TEN) Patients with any mental illness, including dementia, mental changes, which may cause difficulties understanding the informed consent and related questionnaires; Patients with serious uncontrollable diseases, which may interfere with the therapies in this study; Patients with other active malignancies in the past 5 years excluding those with completely cured basal or squamous skin cancers, superficial bladder cancers or primary breast cancers without need of follow-up treatment; Subjects receiving systemic steroids or steroid inhalants; Patients who have received tumor immunotherapy (including monoclonal antibody against PD-1, PD-L1, PD-L2, CD137 or CTLA-4, or cell therapy) in the past 4 weeks; Subjects allergic to immunotherapies or related drugs; Patients with metastatic lesions in meninges or central nervous system, or clear evidence of central nervous system diseases with continuous significant symptoms in the last 6 months; Patients with NYHA class II heart failure, or hypertension incontrollable by standard care, or medical history of myocarditis, or heart attack within a year; Subjects who have received or are going to receive organ transplantation; Patients with active bleeding; Patients with incontrollable pleural or abdominal fluid that needs clinical treatment or intervention; Patients as determined by the investigators to be inappropriate for the study.