This study was conducted to investigate the physicochemical properties of the ethanol extracts and soluble dietary fiber from Cassia tora L. seed. The proximate composition of Cassia tora, soluble solid contents, color intensity and contents of emodin and rhein of Cassia tora extract, molecular mass distribution, sugar contents and viscosity of soluble fiber from Cassia tora were analyzed. Cassia tora contains 12.6% of moisture, 5.2% of ash, 13.4% of crude protein, 7.2% of crude fat, 8.8% of insoluble fiber and 48.3% of soluble fiber. The effects of extract condition on soluble solid contents, color intensity and contents of emodin and rhein of Cassia tora extract were investigated. The soluble solid contents were higher in 70% or 50% ethanol extracts than those in 100% ethanol extracts and showed highest value in grind sample extracts. In Hunter's color value, 100% ethanol extracts and whole Cassia tora sample extracts were higher in L and b value, but on the contrary, were lower in a value, than those of the other. The highest emodin and rhein contents were observed in 70% and 50% ethanol extracts, respectively, and showed higher value in room temperature extracts than in heating extracts. The molecular mass of soluble fiber from Cassia tora seed was estimated by gel filtration chromatography. Most soluble fiber(80%) exhibited a molecular mass range of between 50～2000 kDa. The major sugars of soluble fiber from Cassia tora seed were identified as xylose, mannose and galactose. The apparent viscosity of 0.5% soluble fiber from Cassia tora seed was 33 mPas showing a higher value than pectin or xanthan gum.