This study analyzed gender segregation across fields of study and gender wage gap changes for college graduates from 2011 to 2019. Minigating the segregation across fields of study can reduce the gender wage gap. However, increased compensation for male-dominated fields of study and reduced compensation for female-dominated fields of study due to changes in the industrial structure could increase the gender wage gap. Therefore, the gender wage gap within the year was decomposed by factor using the Blinder-Oaxaca decomposition method, and the change in the gender wage gap between years was decomposed by factor using the Juhn-Murphy-Pierce decomposition method. In addition, the types of collage were analyzed separately to examine according to the level of skill. According to the analysis, the change in the level of gender segregation across fields of study was not significant, which did not significantly affect the change in the gender wage gap. On the other hand, the relative wage level of the engineering field increased around the highly skilled group, and the gender wage gap increased. Therefore, easing the gender segregation across fields of study, which is heavily influenced by individual choice before gender occupational and industrial segregation, suggests that it may contribute to the reduction of the gender wage gap in the labor market.