Abstract: A peptide consisting of an amino acid sequence represented by any one of SEQ ID Nos. 1 to 76 of the present invention, a peptide consisting of an amino acid sequence in which one or several amino acids are substituted, deleted, inserted or added in these amino acid sequences, and having an ability to bind to, or to be taken into an activated vascular endothelial cell, or a peptide containing the above peptide as a partial sequence, and having an ability to bind to, or to be taken into an activated vascular endothelial cell is a novel peptide ligand specifically binding to a neovascular endothelial cell, and such a ligand can be effectively used for treating and diagnosing a disease accompanying vascularization such as a solid tumor.