The recovery of the oil reservoirs in particular carbonate reservoirs decreases gradually after several years and incredible oil remains in the reservoir. This is due to the fact that the inherent energy (oil expansion, solution gas drive, aquifer drive) of reservoirs reduces by production. Hence, the enhanced oil recovery techniques (EOR) are employed to mobilize and produce the residual oil in the reservoirs. One of most common used EOR methods is low salinity water injection where the salinity of the water is improved to enhance the oil recovery. The dominant mechanism in this method is that the injected brine interacts at the rock-oil-brine surface such that the wettability alters towards the brine. Previous studies have shown that low salinity water injection is function of several factors such as rock type, the composition of the injected water, the amount of irreducible water saturation, etc. The experimental studies of the carbonate rocks are less available. In this research, several spontaneous imbibition test was carried out using carbonate rocks in presence of low salinity water at the various rock and fluid conditions in order to investigate the impact of various parameters on the oil recovery. The results indicated that the diluted sea water can improves the oil recovery. The highest recoveries obtained the optimum salinity of 20 times diluted sea water. This experimental study indicated the positive effect of the increasing temperature on the oil recovery. The imbibition tests revealed that the amount of connate water saturation in the core can positively affect the imbibition rate and subsequently increases the oil recovery. The impact of rock permeability was also investigated on the oil recovery during spontaneous imbibition. The oil recovery improved in the low permeable core compared to the high permeable rock sample. In order to examine the impact of the rock type, one test was performed using the sandstone core sample and the results was compared against the carbonate rock at the same salinity of the brine. The results demonstrated higher oil recovery from the sandstone rock than the carbonate sample. The ion concentration and PH of the brine were measured at the beginning and end of each test in order to analyse the ion exchange and other mechanisms occurring during spontaneous imbibition. Key Words Spontaneous Imbibition, Low Salinity, Sea Water Dilution Effect, Initial Water Saturation Effect, Carbonate Rock.