Based on the MASNUM wave-tide-circulation coupled numerical model, the temperature structure along 35°N in the Yellow Sea was simulated and compared with the observations. One of the notable features of the temperature structure along 35°N section is the double cold cores phenomena during spring and summer. The double cold cores refer to the two cold water centers located near 122°E and 125°E from the depth of 30m to bottom. The formation, maintenance and disappearance of the double cold cores are discussed. At least two reasons make the temperature in the center (near 123°E) of the section higher than that near the west and east shores in winter. One reason is that the water there is deeper than the west and east sides so its heat content is higher. The other is invasion of the warm water brought by the Yellow Sea Warm Current (YSWC) during winter. This temperature pattern of the lower layer (from 30m to bottom) is maintained through spring and summer when the upper layer (0 to 30m) is heated and s Based on the MASNUM wave-tide-time cross-section numerical model, the temperature structure along 35 ° N in the Yellow Sea was simulated and compared with the observations. One of the notable features of the temperature structure along 35 ° N section is the double cold cores phenomena during spring and summer. The double cold cores refer to the two cold water centers located near 122 ° E and 125 ° E from the depth of 30m to bottom. The formation, maintenance and disappearance of the double cold cores are discussed. At one reason is that the water there is deeper than the west and east sides so its heat content is The other is invasion of the warm water brought by the Yellow Sea Warm Current (YSWC) during winter. This temperature pattern of the lower layer (from 30m to bottom) is maintained through spring and summer when the upper layer (0 to 3 0m) is heated and s