This study was carried out to investigate the thermal stability of gingerol from Ginger and effect of its concentration on the oxidation of soybean oil. After Heating gingerol, the contents of remained gingerol was measured by HPLC. After heat treatment at $105^{circ}C$ for 3 hours, 94.5% of gingerol was remained, whereas at $165^{circ}C$ for 30 min., only 10% of gingerol was remained. Crude gingerol was also added to soybean oil at the concentration of 0.02%, 0.1% and 0.2% by weight of oil, respectively. The oils with crude gingerol were heat-treated at $105^{circ}C$ for 5 hours and $165^{circ}C$ for 30 minutes, respectively, and then the heat-treated oils were incubated at $45^{circ}C$ for 25 days. The peroxide value of the oils was measured in order to estimate the antioxidant activity of crude gingerol compared with BHT. In the soybean oil heated at $105^{circ}C$ for 5 hours, crude gingerol showed antioxidant activity at all concentration and the activity was more effective than 0.02% BHT. And during the storage of the heat-treated oils at $45^{circ}C$, the antioxidant activity of crude gingerol increased in direct proportion to its concentration. In the soybean oil heated at $165^{circ}C$ for 30 minutes and then stored at $45^{circ}C$, the antioxidant activity of crude gingerol increased in direct proportion to its concentration.