An ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry method coupled with principal component analysis was developed and applied to the identification of Cornu Antelopis, Cornu Bubali, Cornu Naemorhedi, and Cornu Bovis. The data obtained from the trypsin-digested samples were subjected to principal component analysis to classify these four cornua. Additionally, marker peptides of the cornua were determined by orthogonal partial least-squares discriminant analysis, and fragmentation tandem mass spectra of these marker peptides were evaluated. The results from this study indicate that the proposed method is reliable, and it has been successfully applied to the identification of variants of cornua commonly used in traditional Chinese medicine.