Two-phase flow is found in daily life as well as in the field of industry, which consists of three phases, namely liquid-solid, gas-liquid, and gas-solid. The fundamental characteristics of two-phase flow include flow pattern and flow pattern maps, void fraction, and pressure gradient. Some problems related to the pressure gradient comprise of the superficial velocity and viscosity of fluid mixture flow. This research discussed the significant effect of liquid viscosity in two-phase flow pressure gradient to find out the influence of liquid velocity, and also both superficial gas velocity (JG) and liquid superficial velocity (JL) on the pressure gradient. This research used a capillary pipe with a diameter of 1.6 mm. The fluid used was a gas-water mixture and glycerin with a concentration of 40%, 50%, 60%, and 70%. The pressure drop was measured using a pressure transducer and recorded by data acquisition. The result showed that the value of the two-phase flow pressure gradient was affected significantly by the number of liquid viscosity. The higher liquid viscosity leads to an increase in the twophase flow pressure gradient. The pressure gradient was also effected either by liquid or gas superficial velocity, namely, the higher the superficial velocity of either by liquid or gas, the higher the pressure gradient.