This study was carried out to investigate the physical and chemical properties of teat cup liners. The hardness of the liners was $50~67$, and their fatigue to failure 38-1,185 cycles. The elongation and tensile strength of these liners were about $134 kgf/cm^2;and;473\%$, respectively. The infrared spectrum and the gas chromatogram revealed that the liner A was consisted of NR, SBR, and BR, with a composition ratio of 60:20:20 (part per hundred rubber). The raw rubber materials used for liners B to G, on the other hand, were NBR only. However, the liner H was made of silicon rubber. The thermogravimetric analysis showed that the liners tested in this study contained raw rubber material, carbon black, organic compounds and metallic compounds.