Partial least squares (PLS) cluster analysis, based on PLS regression procedure with a self-organizing mechanism, is a novel data analysis method of spectrum. PLS cluster was first used to classify simulated dataset, and present the general properties and validity. Then it was used to aerosol laser time-of-flight mass spectra data, showing correctness and successful application in practice. Finally, this method was applied to mixed spectra dataset of aerosol particles of CaCl2, MgCl2, NaCl and KCl. By examing the statistical properties of obtained dendrogram plots and nodes, the reason of clustering and misclassifying was obtained. It demonstrates the application potential of PLS-Cluster in individual aerosol particle spectra.