Songkhla Lake is the largest natural lake in Southern Thailand which covers 3 provinces; Songkhla, Phattalung and Nakorn Si Thammarat. This lake is an ecosystem rich in biodiversity due to the effect of sea water from the gulf of Thailand and freshwater from the mainland. Currently, Songkhla Lake has deterioration and shallowness problems due to human utilization as well as climatic and geographical changes. This study aimed to investigate the role of Sonneratia caseolaris on sedimentation to delay the shallowness of the lake. The sedimentation rate at the lowerlation section and compare the Sonneratia area with the waterbed in monsoon and dry season. Data on sedimentation rate were collected using 30 cm tall* 5 cm internal diameter cylindrical particle traps. The samples were collected from 10 stations (4 replicates for each station) and compare the Sonneratia area with the waterbed in monsoon and dry season. It was shown that the suspended sediment at Sonneratia area (0.95 grams per day) in the monsoon season was higher than that at the waterbed area (0.29 grams per day) (P