The purpose of this study was to explore what key words were related to parenting stress in web documents on social media and how these words were clustered into groups by using a semantic network analysis. We analyzed 33,467 web documents that included “parenting stress” or similar terms in the Korean language and were posted on online communities, blogs, web boards, or Twitter from January 1, 2016 to December 31, 2018. The key words that were highly related to parenting stress were “children,” “husband,” “mom,” and “housework.” The word “time” had the highest centrality, which means that it had the strongest connection with other key words and had a powerful influence on them. Our CONCOR analysis, classified the top 50 key words into four clusters: (a) individuals and behaviors related to parenting, (b) family and work, (c) issues related to parenting (d) counseling and treatments. These results show that in regard to parenting stress in Korean society, there are active discussions on work-family conflict, gender issues, and the need for support to reduce the difficulties of parenting.