Palm leaf manuscriptsarea kind of the oldestliterature with significant historical and literary values.The leaves are easilydamagedby external factors which can result in disea- ses.Water stainsareone of the most common diseaseson palm leaf manuscripts.They are per- meable contamination depositsthatcan affect the appearance of palm leafmanuscriptsand even damage the subjects'stability.In this paper,visible-reflected images andultravioletfluores- cence images oftwo sets of palm leaf manuscript collectionsare captured.Physical parameters- including pH values and chromatic aberration in water-stain and non-water-stain areasare measured by portable pH meter and colorimeter.The results show that"tideline"is more obvious and water-stain areasareeasier to distinguish under ultraviolet light.Meanwhile, pHvalues are all smaller in water-stain areasand the color differencebetween water-stain and non-water-stain areas is obvious.The results of micro-X-ray fluorescence and Fourier trans- form infrared spectroscopy coupled with ATR show that elements including K,Ca,P,S, and Mn are enriched in water-stain areas,with the decrease of the relative contents of cellu- lose and hemicellulose.Acomprehensive determination methodof water stain on palm leaf manuscripts based on nondestructive techniquesis first establishedin this study,whichpro- vides a deep understanding ofwater stain pollution.The method established in this study is meaningfulfor the scientific and rational preservation of palm leaf manuscriptsand can be a di- rection for furthercleaning and removal of water stain pollution.