Soil salinity and sodicity of coastal paddy are critical factors affecting rice growth. This study investigated the temporal changes in salinity and sodicity of coastal paddy soils on reclaimed tideland (RTL) in southwestern Korea between 2018 and 2023. Soil samples were collected from a total of 139 paddy fields in five RTL districts and inland lake water samples were also collected. The soil and water samples were analyzed for salinity and sodicity parameters including the electrical conductivity (EC) and sodium adsorption ratio (SAR). Although literature suggested that coastal paddy soils tend to be gradually desalinized with rice cultivation after reclamation, in this study, both salinity and sodicity of the coastal paddy soils tended to increase by 0.4 - 7.7 dS m-1 for EC and by 6.3 - 31.7 for SAR between 2018 and 2023. These changes in EC and SAR were not correlated with sand content, which affects salt movement in soils. Rather than, EC and SAR of coastal paddy soils on average across the paddy fields for each RTL district in each year were closely correlated with those of inland lake water, which is the source of irrigation for paddy fields. These results imply that salinity and sodicity of the coastal paddy soils are primarily linked to the irrigation water quality, whi...