The purpose of this study was to investigate the color stability of 2 light - polymerized veneer resins and 3 heat - polymerized veneer resins. Five specimen discs of each brand were immersed in distilled water at $37^{circ}C$, in darkroom for 120 days. The distilled water was changed on every third day to prevent contamination from micro - organisms. The color characteristics of all the samples were measured by computer controlled spectrophotometer. The appearence was characterized by means of the $L^*$, $a^*$ and $b^*$ uniform color space(CIELAB) and total color difference was calculated. The following results were obtained 1) ${Delta}E^*ab$ - value in all brand except IS is were greater than 1 perceptable in visual evaluation. 2) ${Delta}E^*ab$ - value in VI, IS and VG were lower than upper limit of acceptablilty(3.3 in ${Delta}E^*ab$). DC was the worst in color stability and was changed into yellow color.