Anindia Resty Syafira, 2023. Lead (Pb) Heavy Metal Content in Mangrove Sediments in the Graha Indah Balikpapan Mangrove Center Area, East Kalimantan (Supervised by Irwan Ramadhan Ritonga and Mohammad Sumiran Paputungan). Human activities in the Balikpapan coastal area such as industry, shipping, ports, and residential areas have the potential to release waste into coastal ecosystems. One of the toxic wastes to aquatic biota in coastal ecosystems is Lead (Pb), which metal may precipitate and accumulate in mangrove sediments. The purpose of this study was to determine the Pb content and the level of contamination of Pb contaminants in sediments. Sediment samples were taken from 6 different stations using PVC pipes immersed in the Graha Indah Mangrove Center area, Balikpapan. Sediment samples were acid digested and analyzed using an Atomic Absorption Spectrophotometer (AAS) AA-7000 at a wavelength of 217 nm. It was found that the concentration of Pb in the sediment was between 2.23 and 14.0 ng/g with an average of 6.24 ± 3.09 ng/g (dry weight). Comparison of Pb content between stations differed significantly (p0.05) when compared based on the source of the pollutant. Variations in the Pb content in sediments could be influenced by human activities as a source of Pb waste at the study site, water circulation from rivers carrying organic and inorganic materials containing Pb, as well as the influence of tidal currents from Balikpapan Bay. In general, the Pb content in sediments was not exceed quality standards, the contamination factor value was low (CF