This dataset includes total organic carbon (TOC), total nitrogen (TN), stable carbon isotope (δ13C) and radiocarbon activity (expressed as fraction modern - Fm) of TOC, as well as mineral surface area (SA) and grain size of 44 sediment samples from 28 rivers on Luzon of Philippines. The samples were collected during July 2007. TOC, TN, and stable δ13C of carbonate-free sediments were measured by an elemental analyzer interfaced with an isotope ratio mass spectrometer (EA-IRMS; Flash EA 1112 HT-Delta V Advantage). Duplicate analyses of three samples show the reproducibility of TOC, TN, and δ13C are ±0.02%, ±0.01% and ±0.02‰, respectively. Radiocarbon measurements of TOC were performed on an accelerator mass spectrometer (AMS) at the Laboratory of Ion Beam Physics, ETH Zürich. The results are reported as fraction modern (Fm). The absolute error of Fm values for all samples is better than ±0.01. SA of sediments were determined using 5-point Brunauer-Emmet-Teller (BET) N2 adsorption isotherm on a NOVA 4000 surface area analyzer, with a analytical precision of better than ±1%. Grain size distributions were measured using a Malvern Mastersizer 2000, with a relative precision better than 0.02%.