The stratigraphy and evolution of the intertidal deposit of Gunhung Bay, west coast of Korea, have been studied by analyzing surface sediments, core sediments and subbottom profiles. The surficial sedimentary facies consists of upper mudflat, mixedflat and lower mudflat from high tide level to low tide level. The tidal deposit above the acoustic basement is 5 - 20m thick and can be divided into two sedimentary sequences by a mid-reflector. The boundary of them is identified by long core data. The lower sedimentary unit (sequence B) consists of semi-consolidated, brown sandy muds and is interpreted to be deposisted during Riss-Wurm interglacial period. The upper sedimentary unit(sequence A), which overlies the sequence B unconformably, is about 10m thick and consists of Holocene intertidal sediments. The sequence A consists of mudflat facies at lower part and mixedflat facies at upper part. It indicates that the sequence A is a transgressive sequence. Many V-shaped erosional patterns at the unconformable contact of sequence A and sequence B indicate the existence of old tidal channels formed during the low sea level of the last glacial period. The long-term accumulation rate of sequence A is considered to be 2㎜/yr from core data and it is coincident with the accumulation rate determined by Pb-210 for the PVC core.