Lubricant is a special additive that has been added into the drilling fluid to enhance its performance in borehole under extreme conditions. A laboratory experiment is conducted to study the properties of different bio-lubricants effect in water-based drilling fluid. The filtration test was done to monitor the rate at which the drilling fluid is forced from a filter press under specific conditions to measure the fluid loss and filter cake. The rheology properties measured from rheology test were plastic viscosity, yield point and gel strengths. This research used two different types of bio-lubricant which were Guar gum and Castor oil. This paper presents preliminary and predictive bio-lubricant additives effect on water-based drilling fluid. The result shows that by adding certain amount of these bio-lubricant, it will improve the performance of water-based drilling fluids. Findings in this research have shown that some of the Guar gum property is better than Castor oil and some of the Castor oil property is better than Guar gum which shows that careful selection is needed when applying these bio-lubricant. © 2018 Elsevier Ltd.