This disclosure relates to be used for treating cancer and increase the peptide compounds and conjugated compound, preparation process, method and their purposes of the cell internalizing of peptide compounds.The peptide compounds are selected from:Such as SEQ ID NO:GVRAKAGVRNMFKSESY shown in 9;Such as SEQ ID NO:GVRAKAGVRN shown in 10 (Nle) FKSESY;With such as SEQ ID NO:YKSLRRKAPRWDAPLRDPALRQLL shown in 11;And wherein at least one blocking group and/or at least one labelled reagent are connect with the peptide compounds.