Above-ground tree biomass was estimated for the low-land forests of Taman Negara, Pahang. Five transect lines measuring at 100 × 20 m of each were established for this study. The transect lines consist of a total of 439 trees. The tree height and the diameter at breast height (DBH) of all trees (≥ 10 cm) were measured in each transect line. Kato et al. (1978) function was used to estimate the three components of above-ground tree biomass viz: stem, branches and leaves. The total above-ground tree biomass for all transect lines in the study area were computed from the summation of these biomass components. The means of above-ground tree biomass were at the ranged of 612.2 kg to 983.6 kg. Analysis of Variance (ANOVA) test procedure revealed that there is no significant difference in the means of above-ground biomass between transect lines. Results of the analysis suggests that the factors exist within different localities has no influence on the estimated above-ground tree biomass. Hence, it is hoped that this study can provide useful information with regards to the biomass estimation as an indicator of tree carbon stocks.