Surface potential measurements deduced from electrophoretic mobility were made on organic shale from the potential source rocks from Central Luconia, offshore Sarawak basin, Malaysia, with the aim of determining the ionic binding properties of the rocks. Variations in zeta potential were attributed to protonation and deprotonation reactions occurring on amphoteric sites (Al-OH and Si-OH) of kaolinite, which is the dominant clay mineral phase among the shales. Dissolution of Al3+ from the crystal lattices of muscovite and contribution from illite were also considered as surface potential variants in specific samples. The influence of shale chemical composition and organic matter content on surface charge characteristics was studied by correlating results from total organic content analyses, X-ray fluorescence spectroscopy, and isoelectric points. Organic matter showed no relationship with isoelectric points, but an enhancement of isoelectric points was observed with increasing ALO3 and Si/Al ratios. © 2018. All Rights Reserved.