Hydrocarbon reserves estimation process primarily involving calculation of water saturation obtained from direct resistivity measurement during a logging operation. The resistivity value recorded directly after drilling process in open-hole condition is considered as key input for reserves estimation. Water saturation value can be determined by Archie's equation as the water saturation model in claen sanstone. Formation evaluation in sandstone rock becomes more challenges as Archie's equation only suitable for the clean sand formation and high dependency of Archie's parameters on rock properties. Determination techniques of Archie's parameters are relatively well known and validated for clean sand formation, but sandstone with present of clay are heterogeneous. Correct determination of Archie's parameter is important in the process of reservoir evaluation. In certain cases of sandstone rock, there are considerable variation in pore type and pore pattern distribution, so, it becomes more complicated due to the parameters in Archie equation highly rely on wettability phase inside the rock, lithofacies properties and distribution of pore pattern of the rock. An accurate determination of Archie's parameters is important in computing the water saturation and estimation of hydrocarbon in place. The uncertainty in Archie's parameters mainly influenced by tortuosity factor (a), cementation exponent (m) and saturation exponent (n). This work focuses on the measurement of Archie's parameters on sandstone core samples from Malaysian sandstone reservoir. Three techniques for determination of Archie's parameters a, m and n will be implemented: Conventional technique, Core Archie's Parameter Estimation (CAPE) and three-dimensional regression technique (3 D). By using result obtained from three different technique water saturation graph were produced to observe a symbolic difference of Archie's parameter. The difference could be primarily attributed to showing the uncertainty level of Archie's parameters in sandstone rock. It was very obvious that the accuracy of Archie's parameters has great impact on the calculated water saturation values in sandstone reservoir due to highly stress region will reduced electrical conduction. © Asia Petroleum and Geoscience Conference and Exhibition, APGCE 2017.All rights reserved.