Robust warming and frequent extremely high sea temperature events (marine heatwaves, MHWs) have been observed in the coastal China seas (CCS) over the past decades, causing a series of ecological disaster, including mass mortality of marine organisms and outbreaks of harmful algal blooms. This paper presents a comprehensive review of the research progress involving the warming and marine heatwaves in the CCS, including the characteristics and causes of long-term warming trend and MHWs, as well as their ecological impacts and adaptation strategies. Under the combined influences of the East Asian monsoon and Kuroshio, the sea surface temperature (SST) in the CCS, especially in the East China Sea (Bohai, Yellow and East China Seas), has shown an enhanced response to global warming, with annual mean increases of 1.02 ±0.19°C and 1.45±0.32°C during the period of 1960-2022, respectively, with significant inter-decadal and inter-annual variability. In addition to the influence of large-scale air sea interaction such as ENSO and PDO, SST changes are also directly affected and jointly affected by the East Asian Monsoon changes and the Kuroshio meridional transport. The ocean warming has caused rapid northward migration of geographic isotherms and seasonal phenological changes (spring arrives earlier and fall begins later than normal), resulting in the changes in the growth rhythm, geographic distribution, community structure and ecological service functions of marine organisms. Frequent extreme MHWs have caused devastating disasters to some marine ecosystems such as coral reefs and aquaculture. In the future, the mid-high latitudes of CCS will be simultaneously exposed to the enhanced warming, deoxygenation, acidification, and reduced productivity; and sever climate tipping points of marine ecosystems such coral reef ecosystems in the South China Sea are very likely to triggered in the near future. There is an urgent need for in-depth research on the physical processes and predictability of marine heatwaves, as well as the forecasting and early warning systems. Furthermore, transformative climate action measures should be developed to enhance the climate resilience of ocean systems, and strong mitigation measures need to be taken as soon as possible to slowdown global warming.