The black neutral pen ink is mainly composed of solvent,pigment,thickening agent,stabilizer and other chemical additives.The chemical composition of the black neutral pen ink produced by different manufacturers is different and the chemical composition of the different black neutral pen ink produced by one manufacturer is also different.This provides the basis for the kind discrimination of neutral pen ink. In this paper,the Fourier Transform Infrared Spectroscopy(FT-IR)is used to determine the composition of 32 kinds of black neutral pen ink on the market.According to the peak position,peak number,peak form and peak strenth in infrared spectra,the black neutral pen ink produced by different manufacturers or the different black neutral pen ink produced by one manufacturer can be discriminated.This method has the features of quickness,accuracy and high sensitivity and is nondistructive to samples.