Acacia mangium Willd. is categorized as an invasive species in the revegetation area of coal mining. The presence of A.mangium causes a shortage the organic matter in the revegetation area. The abundance of A. mangium biomass could be used as a source of organic material for soil enhancer to improve soil fertility. The objective of this study was to develop allometric models of Acacia mangium and to estimate the potential above-ground biomass of A. mangium in PT Wahana Baratama Mining (PT WBM). This study was conducted in February-April 2019. A. mangium population and distribution were collected through vegetation inventory with 0.5% sampling intensity. The allometric models were established using a destructive method. The above-ground biomass allometric model for the four diameter classes are as follows: seedlings (B = 0,002002 - 0,02469D + 0,07322D2 with R2(adj)= 99,38%), saplings (B = 2,754 - 1,742D + 0,4093D2 with R2(adj)= 99,89%), poles (B = -9,16 - 1,153D + 0,5007D2 with R2(adj)= 99,96%), and trees (B = 0,134741D2,38 with R2(adj)= 96,94%). The allometric models were used to estimate the above-ground biomass potential total of A. mangium by using inventory data. The inventory result showed that the mean density of A.mangium is 13.187 individuals/ha with a mean diameter of 5,64 cm. The potential above-ground biomass of A. mangium in PT WBM revegetation area is estimated at up to 51.022,59 tons. The above-ground biomass of A. mangium has potential value to be utilized as a soil enhancer as well as meet the needs of organic material for the whole PT WBM revegetation areas.Keywords: above-ground biomass, coal mining, Acacia mangium, reclamation, revegetation