Stable PAMAM(polyamidoamine) capped ZnS (zinc sulfide) QDs (quantum dots) were prepared and characterized with UV-Vis spectrum and PL(photoluminescence) emission spectrum on the base of coordination of Zn2+ ions with PAMAM dendrimers. The results show that Zn2+ ions coordinated with N atoms of PAMAM ligand and the saturated coordinating time is about 6 h; PAMAM capped ZnS QDs emitted strong blue light under the irradiation of UV light at the wavelength of 365 nm, and the PL emission peak is at about 500 nm. Finally, the prepared PAMAM capped ZnS QDs were applied in the fluorescent labeling of latent fingerprints on tinfoils; Latent fingerprints emitting strong blue light and were successfully detected with good resolving rate.