South Korea's economic development level is quite similar to ours, given that both countries are developed economies and 77% of our export are overlapping. The economic structural similarities of the two countries lead to their relationship featured with more competition than cooperation in the global market. Moreover, enterprises of both countries share the same strategy viewing Vietnam as a manufacturing hub of their business operations and a gateway to ASEAN. As a result, Taiwan was Vietnam's biggest investor for quite a long time until 2012 when Japan and South Korea outperformed Taiwan in Vietnam's investment. In this paper, the author intends to explore South Korea-Vietnam relations in general but with a particular focus on the bilateral economic relations under President Park Geun-hye from three angles, bilateral trade, South Korea's investment in Vietnam and South Korea's economic assistance to Vietnam. Then it will be concluded by prospects and challenges as well as implications for Taiwan.