<p>Marine heatwaves (MHWs), recognized for their significant impact on marine ecosystems, have become a key topic in physical oceanography. The current definition of MHWs, which solely depends on sea surface temperature while neglecting dynamical factors, may cause overlaps with other oceanic phenomena such as mesoscale eddies. However, the related research remains incomplete. The South China Sea (SCS), hosts a high frequency of both MHWs and mesoscale eddies, making it an ideal region for investigating the interaction between these phenomena. In the current investigation, we compared MHWs identified from OISSTV2.1 data with mesoscale eddies from the Meta 3.2 dataset. Our findings indicate that 37.79% of MHWs overlap with mesoscale eddies during their lifetime, with 3.50% remaining within mesoscale eddies throughout their entire duration. Despite cyclonic eddies (CEs) having a slightly larger spatial coverage, anticyclonic eddies (AEs) are more frequently associated with MHWs. indicating that they may better facilitate MHW occurrence and persistence. This can be explained by the dual role of AEs, which not only can themselves be identified as MHWs but also promote their formation by inducing seawater convergence. Additionally, 16.31% (17.51%) of CEs (AEs) contain MHWs, and 3.23% (3.12%) of CEs (AEs) are entirely identified as MHWs. This analysis contributed to a deeper understanding of MHWs and provided new insights into the relationship between MHWs and mesoscale eddies.</p>