The coastline is interaction zone between land and sea. It is an important ecotone for global ecosystem conservation. The coastline classification is organization of varied coastline into classified types according difference rules. It is the foundation for coastline protection, use and marine resources integrated management, however, the coastline classification has stillnot been addressed systematically even nowadays. Aimed to clarify the coastline classification system, this article discuss the coastline classification system according to natural attribute and spatial pattern, exploitation, functional use, temporal scale, management requirement, ect of coastline. First, the coastline can be divided into natural coastline and man-made coastline. The natural coastline is result of natural interaction between sea and land, while the man made coastline is sea-land demarcation line which forms by cofferdam or dyke by human sea exploitation activities. Then the coastline is divided into rocky coastline, sandy coastline, silt coastline, biological coastline and estuary coastline according to geological characteristics in intertidal zone and coastline spatial pattern. The rocky coastline is comprised by rock in the intertidal zone and the contour of the coastline is very irregular. The sandy coastline is made up by sand and gravel in the intertidal zone and its contour is straight. The silt coastline is made up by silt in the intertidal zone and distributes near the estuaries. The biological coastline is formed by biological function, such as mangrove coastline and coral reef coastline. While the estuary coastline is surface demarcation between river and sea in estuary region. Third, the coastline can be divided into fish coastline, port coastline, industry coastline, tourism and leisure coastline, urban coastline, mineral and energy coastline, protection coastline, special purpose coastline and unused coastline. The fish coastline is used for fishing and fish resource conservation. The port coastline locates in the port area and connect with deep water region. The industry coastline is connect with industrial park or industrial region. The tourism and leisure coastline is locate in tourism region, which include coast landscape coastline, bathing coastline and amusement coastline. The urban coastline distributes near the urban,where the public can touch freedom. The mineral and energy coastline is use for sea salt production, oil-gas field and other mineral production. The protection coastline is locate in marine protected areas or coastline which need protected. The special purpose coastline include tide prevent coastline, education and research coastline and others. In addition, the coastline can be divided intohistorical coastline, current coastline and future coastline in temporal scale. And it is also can be divided into management coastline and actual coastline, the mainland coastline and the island coastline, erosion coastline and stable coastline, ect. Then some questions about coastline classification is discussed to distinguish the typical coastline, finally.