The purpose of this study was to compare the color of various composite resins with different thickness. To evaluate the color change of the specimens (n = 10), disk-shaped specimens (diameter: 8 ㎜, thickness: 1, 2, and 3 ㎜) were filled with 10 composite resins. After light-curing, the specimens were removed from the mold and kept in a dark chamber at 37℃ for 24h. The colors of all specimens were measured by a spectrophotometer based on CIE L*a*b* system, and the color difference (ΔE* ) and translucency parameter (TP) were calculated. Data was statistically analyzed by ANOVA and Tukey’s test. For the kinds of composite resins, there was no significantly different between ΔL*<SUB>12</SUB> (L* in 2 mm thickness -L* in 1 mm thickness) and ΔL*<SUB>13</SUB> (L* in 3 mm thickness -L* in 1 mm thickness) but significantly different between Δa*<SUB>12</SUB> and Δa*<SUB>13</SUB> and between Δb*<SUB>12</SUB> and Δb*<SUB>13</SUB>. For resin thickness, there was no significantly different between ΔE*<SUB>12</SUB> and ΔE*<SUB>13</SUB>. All the ΔE* values of specimens were below the clinical perceptible range (ΔE* <3.3). For TP, as the resin thickness increased, the values of TP was decreased and there was significantly different between ΔTP<SUB>12</SUB> and ΔTP<SUB>13</SUB>. In conclusion, the color change of composite resin depending on thickness was too low to be perceived by the naked eyes and translucency parameter of composite resin was decreased as the resin thickness increased.