With the high demand of oil and gas consumption, oil is required for more production. Fang oilfield is one of the main oilfields in Thailand. An enhanced oil recovery method especially alkaline-polymer flooding is an essential technique to improve oil production. It involves an injection of alkaline to lower the interfacial tension (IFT) between oil and water and polymer for improving the mobility ratio to produce more oil. In Fang oilfield, a light oil recovery is improved by using the solution to reduce IFT of oil and water. In this study, sodium hydroxide (NaOH) and hydrolysed polyacrylamide (HPAM) are used as alkali and polymer to lower the IFT with different conditions. The aim of this work is to measure the IFT and to assess the effects of pressure, temperature, concentration and salinity on IFT reduction for oil from Fang oilfield. The results present that the concentration of the chemical plays a key role for IFT reduction accounting for 99.49 %. IFT decreases with an increase in temperature up to 49.30 %. The effect of pressure is insignificant for IFT reduction. Salinity can increase IFT for 94.74 % at the low alkali concentration while HPAM could be more benefit in other aspects such as the mobility control process. The outcome of this work can be used as a fundamental data to enhance more oil recovery with the new technique for Fang oilfield.