Abstarct: Nowadays, both reduction in oil resources and efficiencies of reservoirs caused a need for Enhanced Oil Recovery methods. Primary and secondary methods approximately have no effect on these kinds of reservoirs. Consequently, tertiary recovery like CEOR (Chemical Enhanced Oil Recovery) seems to be the only practical approach to improve oil recovery. One of the CEOR methods to tackle these problems is ASP flooding which can be really helpful in some types of reservoirs. It should be noted that a large number of reservoirs are carbonates which have a great deal of trapped oil. Therefore, these reservoirs could be a good candidate to be employed for this method. The main goal of this thesis is finding a proper formulation of ASP in a typical limestone carbonate by means of experimental methods. Two kinds of core samples with high and low permeability were used in these experiments which the high permeable and low permeable rocks were prepared from the outcrop of Babakoohi in Fars Province and a reservoir in south of Iran, respectively. The crude oil was prepared from a reservoir in south of Iran. The brine TDS was around 40000 ppm which the dominant ions were Na+, Cl- and SO42-. In relation to a proper formulation of Alkaline-Surfactant (AS), a combination of CTAB and a nanoparticle (TiO2) as surface active agent and NaHCO3 alkaline were used. In order to gain the proper formulation of AS and concentration of its components, a number of diverse experimental tests were conducted. Vacuum pump was used to saturate the cores with brine and at last they were flooded by core flood apparatus to reach the connate water saturation and initial oil saturation. After this process, core samples were prepared for imbibition process in 40 days of aging process in a sealed pressure vessel at 60 °C and 2000 psia. Totally, imbibition tests were conducted at three different temperatures (25, 40 and 60 °C). To obtain the adequate AS formulation, at first step the mixtures lonely were examined. At next steps, mixtures at constant salinity and temperature were tested. Again, the testing process continued at constant salinity and different temperatures. At last, nanoparticle effect was analyzed. In conclusion, it was observed that temperature increase promotes production growth as we only use modified brine or a typical AS combination. Nanoparticle without different ions usage can cause an acceptable oil production, AS in comparison with solely surfactant usage can increase recovery factor and oil production rate in secondary recovery and AS modified formulation also was succeed in oil production as the tertiary recovery.