Effect of puffing treatment on saponins, total sugars, acidic polysaccharide, phenolic compounds, microstructure and pepsin digestibility of dried red ginseng tail root were tested. Puffing samples of dried red ginsneng tail root were pre-pared at 20rpm, 15 $kg/cm^2$, $120{sim}150^{circ}C$, and for 30 min by a rotary type apparatus of 5 L capacity. Crude saponin content of puffing red ginseng tail root was increased 26.5% compared to non-puffing, especially $Rg_3$ content was increased from 0.49 mg/g to 0.72 mg/g. Total sugar content was not changed, but acidic polysaccharide content was slightly decreased from 7.15% to 6.44% by puffing treatment. Total phenolic compounds was increased from 7.86% to 9.94% by puffing. In terms of individual phenolic compounds, salicylic acid was quantified in puffing tail root, but gentisic acid was quantified in non-puffing. Syringic acid was the most predominant phenolic acid, increased to about 6 times by puffing treatment. On the other hand, gallic acid, p-coumaric acid, caffeic acid and ferulic acid were highly decreased. Microstructure of cross-section in puffing tail root was shown to more uniform shape compared to non-puffing. Pepsin digestibilities of puffing and non puffing red ginseng tail root were 22.4% and 46.2%, respectively (p<0.05). The results indicated that puffing treatment might be useful increasing the bioactive components, preference and digestibility.