Abstract: Objective To explore the possible reasons for betel tooth discolouration by composition analysis. Methods Analyze chemical elements in the stained deposition by XRF. Analyze possible organic ingredients in the stain deposition by FTIR. Results The stained area contains O, C, Ca, P, S, 3 2- 2- Cl, Fe, Mn, Na, protein, PO4, HPO4 Fe, Mn, S and protein., and CO3. Conclusion Betel tooth iscolouration is due to Fe，Mn，S and protein.

Key words: betel tooth, tooth discolouration, composition analysis

摘要： 目的　通过对槟榔牙表面着色沉积物的成分分析,探究槟榔牙着色的可能原因。方法　利用X射线荧光光谱（XRF）分析槟榔牙表面着色沉积物的元素组成；借助傅里叶变换红外光谱仪（FTIR）分析着色沉积物中可能的有机成分。结果　着色区域含有O、C、Ca、P、S、Cl、Fe、Mn、Na等元素。着色区域有机成分中可能含有蛋白质、磷酸根、磷酸一氢根、碳酸根。结论　槟榔牙无机着色与Fe、Mn、S元素相关，有机着色可能与蛋白质氧化有关。

关键词: 着色, 槟榔牙, 成分分析