Inclusion Criteria:

- Age between 18-70 years, male or female.

- ECOG performance status <=2.

- Life expectancy >= 3 months.

- Histologically or cytologically confirmed soft tissue sarcoma (GIST excluded).

- Patients must have had a prior anthracycline and/or ifosfamide in either the adjuvant
or metastatic setting but not more than one regimen.

- At least one measurable pulmonary metastasis tumor lesions according to RECIST 1.1
criteria.

- Laboratory values: Hemoglobin (Hb) >= 90 g/L and no blood transfusion within 14 days,
Absolute neutrophil count (ANC) >= 1.5 x 10^9/L, Platelet (Plt)>= 80 x 10^9/L, Total
Bilirubin (Tbil)=< 1.5 x upper limit of normal (ULN), Alanine aminotransferase (ALT)
and aspartate aminotransferase (AST) =< 2.5 x ULN or =< 5 x ULN if liver metastases
are present, Serum creatinine (Cr) =< 1.0 x ULN, Endogenous creatinine clearance
(Ccr)> 50 mL/min (Cockcroft-Gault).

- Women of child bearing potential must have a negative serum or urine pregnancy test
within 7 days before enrollment and be willing to use effective contraception during
study and for 8 weeks after last IMP administration.

- Willingness to participate in study and sign informed consent form.

Exclusion Criteria:

- Females who are pregnant or breastfeeding or have Childbearing potential unwilling to
use effective contraception.

- Prior therapy with Gemcitabine, Docetaxel and Endostar.

- Subjects participating in other clinical trials within 4 weeks before enrollment.

- Accompanied by rapid progress of organ invasions, e.g.lesion areas are great than one
half of liver or lung or have liver dysfunction.

- Uncontrolled central nervous system disorder or psychiatric illness.

- Current, serious, clinically significant cardiac arrhythmias, symptomatic congestive
heart failure, myocardial infarction before enrollment.

- Patients with abnormal bone marrow function: ANC < 1.5 x 10^9/L, Plt < 75 x 10^9/L,
Hb < 90g/L.

- Patients with renal dysfunction: Cr > 1.5 x ULN.

- Patients with liver dysfunction: Tbil > 1.5 x ULN.

- Uncontrolled brain metastases.

- Unwillingness or inability to comply with the study protocol.