This study was carried out to investigate the some physicochemical properties of Korean red ginseng (Panax ginseng C.A. Meyer) water extract (RGWE) after heated with high temperatures above $100^{circ}C$ for 2 hours. RGWEs were heated at 100, 110 and $120^{circ}C$ for 2 hours by using autoclave. After RGWEs were heated at high temperature for 2 hours without not adjustment of pH, the changes of saponin, free sugars, mineral and color in the RGWEs were investigated. Total ginsenoside content in control was 1.99%, while those of RGWE were 1.65, 1.49 and 1.29% when treated at 100, 110 and $120^{circ}C$, respectively. The contents of total ginsenoside showed decreased tendency as heating temperatures were increased. The ginsenoside-$Rh_{2}$ and $-Rg_{3}$, which have been reported as very stable red ginseng ginsenosides, showed relatively strong spots on TLC when RGWEs were heated at 110 and $120^{circ}C$. In case of free sugars in RGWEs, fructose, glucose and maltose showed high contents when compared with control, while Fe, Ca and Mg ions showed very low contents. Value of L in RGWE treated with high temperature was almost the same with control, while values of a and b were increased. Values of a were increased from -0.86 of control to +0.04, +0.05 and +1.14 when treated with 100, 110 and $120^{circ}C$, respectively. Values of b also were increased from 27.68 of control to 33.61, 33.61 and 37.42 when treated with 100, 110 and $120^{circ}C$, respectively. Values of total color in RGWEs treated with high temperatures, E, were finally increased by values of a and b.