We propose a new method of photoluminescence (PL) measurements, that is, exciting core levels using synchrotron radiation. This method has been applied to characterize CdSe quantum dot (QD) structures in this study. PL spectra of the CdSe QD sample under Zn 2p core-level excitation are slightly different from conventional FL. PL core-level excitation (PLCLE) spectra have sharp Zn 2p(3/2) and Zn 2p(1/2) absorption edges and core-exciton peaks for CdSe QDs. Moreover, the PLCLE spectra reveal interfacial states between ZnSe barrier layers and CdSe QDs. This result indicates that PLCLE is useful as a local probe for the thin films and semiconductor nanostructures.