Embodiments of the invention provide a compound accumulating in an inflammatory site, a diagnostic agent containing the compound in labeled state and its precursor compound for labeling. Such a compound accumulating in inflammatory site may be represented by the following formula (1):Z—Y-Leu-Phe-(X)n-DLys(-(DLys)m-HalB)-(DLys)k-NH2 (1)whereinin the formula (1),Z represents a protective group for an amino groupY represents Met or NleX represents a spacer consisting of one or more of amino acid and/or synthetic organic compoundsn represents 1 or 0m represents 1 or 0k represents 1 or 0 andHalB represents a substituted benzoic acid having a radioactive halogen in an aromatic ring.
