The preparation of red underglaze pigment for stoneware from some chemical agents were studied. These chemical are Fe(,2)O(,3) , FeSO(,4) , MnSO(,4) and Cr(,2)O(,3) . The afore-mentioned chemical agents were then mixed with other materials and then calcined unit it has a stable structure. In addition, the influence of thermal and atmosphere which affected red underglaze pigment were studied. It was found that the red underglaze pigment had given a significantly satisfied results when used together with clear lime glaze. The best red pigment of chrome-tin consisted of 45.5% SnO(,2) , 28.4% CaCO(,3) , 20.5% SiO(,2) , 4.5% Na(,2)B(,4)O(,7) and 1.1% K(,2)Cr(,2)O(,7) , and calcined at 1250 degree C in oxidation atmosphere. Moreover, physical analysis of chrome-tin red and commercial red pigment were compared by X-ray diffactometer. It was found that the red underglaze pigment had tin-sphene structure. The quantitative analysis of Cr(,2)O(,3) by atomic absorption spectrophotometer and X-ray fluorescence spectrophotometer revealed that commercial red pigment no.6006 had more Cr(,2)O(,3) than the prepared red pigment. Spectrum analysis of chrome-tin red pigment were done by using diffuse reflectance spectrophotometer and it revealed the band at 500-530 nm belongs to chromium-droped tin-sphene [CaO. SnO(,2). SiO(,2)]. Infrared spectrum showed (...)(Sn-O) at 353 cm(1) in both commercial and the prepared pigment.