Abstract: In ancient Chinese, 潟 mean saline land. There was not strict orthographic norm in ancient Chinese, and people usually dropped using the orthography and took a similar word to replace it, such as using 泻(瀉), 舄, 舃to replace潟. Lagoon is in fact a local marine waters which is formed because coastal zone separated by barrier spit, sand dam or coral. Lagoon is closely related to潟, not related to泻, 泻湖should be潟湖.

Key words: 潟湖, 泻湖