Lang Suan is a district of Chumphon province, southern Thailand. Lang Suan was originally a mueang reporting directly to Bangkok. During t…Lang Suan is a district of Chumphon province, southern Thailand. Lang Suan was originally a mueang reporting directly to Bangkok. During the Thesaphiban reforms at the end of the 19th century it was put under monthon Chumphon. On 29 April 1917 the district's name was changed from Mueang Lang Suan to Khan Ngein. On 1 April 1932 the province was abolished and its districts were incorporated into Chumphon province. On 14 November 1938 the district's name was changed to Lang Suan.