Sediment pin was used to measure the accumulation of sediment materials in the mangrove ecosystem of Sukol River, Bongabong, Oriental Mindoro, Philippines. The roots of the mangroves trapped the sediments that enter the riverine system. Their source could be from the upland or due to high tide current. Through the use of PVC pole as pins along the study site, the accretion of sediments was captured for data gathering and analysis. The results showed that the technique is useful to discuss the dynamic of sediment capture within the studied ecosystem. This provided an analysis of the beach condition near the riverine mangrove ecosystem. A healthy mangrove structure can provide a sediment budget for the shoreline mitigating coastal erosion.