A method for treating a vascular-related disease in a subject in need thereof, includes administering to the subject a peptide having a sequence Xaa-Gly-Asp. The peptide may have a sequence of SEQ ID NOS: 1, 2, 4, 6 to 10. The vascular-related disease may be edema and/or ischemia caused by blood leakage of blood vessel walls, damages of blood vessels or abnormal angiogenesis.