Wound healing proceeds, fibroblasts play a major role in controlling the composition and amount of extracellular matrix and collagen metabolism. As the amount of collagen product is increased, the scar becomes more thicker and harder. Firmness of the scar can significantly influence the outcome of scar revision depending on the amount of collagen. This study aimed to classify the results of surgical scar revision according to the hardness of the scar and to compare histological differences and effectiveness in scar revision surgery between each classification. We selected subjects who had undergone scar revision and examined their scar pathology and surveyed the satisfaction levels of patients and Vancouver scar scale in each group. As the scar hardness increased from soft to hard, more collagen fiber bundle and elastic fiber tangling were noted. On the other hand, the satisfaction of patients was increased as the scar hardness was decreased from hard to soft. In this study, therefore, we concluded that as the scar becomes harder, the tangling of elastic fibers and the amount of collagen fiber bundles increase. Such patients revealed a robust collagen metabolism, and showed worse results of scar revision.