Horizontal scale and movement of tidal front zone, front in the western regions of Korea in summer are studied in conjunction with numerical model and NOAH-11 satellite data analysis(AVHRR multi -channel sea surface temperature). In numerical model result, tidal mixing is dominant in the southeast region of Hwanghae, near field of Taean, Kyunggi bay, near field of Jangsan cape, Seoan bay, mid-east Chinese coast. But the results of the NOAH infra-red image analysis show that low surface temperature by tidal mixing is clear in the southeast region of Hwanghae, near field of Taean, near field of Jangsan cape but not in the Kyunggi bay, Seoan bay and mid- east Chinese coast in August and September, temperature gradient of frontal zone in the southwest region of Hwanghae is 0.05°∼0.1℃/㎞ and tidal mixing is dominant in the near field of Maenggal kundo and Hajodo and low surface temperature extends southwesrward. Early in August, west-east front(0.2°∼0.6℃/㎞) on the south region of Jindo moves northward and persists at east half on the joining line of Jindo and Sohuksando late September. The axis of front on the west region of Jindo is northeast~sorthwest early in August and moves westward until late September The tidal mixing in the near field of Jangsan cape is dominant in the region between Jangsan cape and Baengyougdo early in August and between Baengyougdo and Daechungkundo in late September. The axis of front on the west region of Jangsan cape is south-north and its temperature gradient is 0.2°∼0.4℃/㎞.