The Lower Chao Phraya River is area that is affected by changing of sea level resulting in two directions of flow and sediment transports depending on the upstream water levels and sea water levels. Th e study of sediment behavior in this area is important
for solving problem about water transportation and water management management. Hydraulics data were collected by Acoustic Doppler Current Profiler, echo sounder and suspended sediment equipment in the Lower Chao Phraya River between November 2015 and
May 2016 2016. It is found that the d iameter of suspended sediment is 0 0.027 mm mm. Sediment settling velocity is 2121.31 m mm/ss. Spring tide
and neap tide are the most effect to behavior of suspended sediment sediment. Sediment load equations are presented by three variable linear equation q = (9x10-5)Q – 0.0002D in spring tide and q = (4x10-5)Q + 0.0032D in neap tide. R2 are equal 0.6484 and 0.6007 respectively.