[en] We investigated radiocesium concentrations in the suspended solids (SS) of two large rivers discharging into the Sea of Japan. Higher ¹³⁴Cs concentrations in SS sampled from upstream area in 2013 (711 Bq/kg-SS) reflected the larger effect of radioactive depositions in western Fukushima Prefecture. However, smaller but less variable concentrations in downstream areas (< 100 Bq/kg-SS) indicated a continual supply of ¹³⁴Cs-contaminated SS from 2013 to 2017. The particulate ¹³⁴Cs concentrations in normal flow conditions were at approximately similar levels with those in coastal waters (<  ∼ 1 mBq/L), suggesting that the impact of SS on the Sea of Japan was negligible after 2013. (author)