Two-phase flow is a stream of the most simple of multiphase flow. The two-phase flow consists of 3 states, namely liquid-solid, gas-liquid and gas-solid. Basic characteristics of two-phase flow include flow patterns and flow pattern maps, vacuum fractions, and pressure gradients. This research will discuss the investigation of pressure gradients in two-phase flow. Pressure gradients are used in the piping industry to determine the pressure of the fluid in the flow in the pipe. This research was conducted in the test section in the form of a glass pipe that has a diameter of 1.6 mm with a slope angle of 450 towards the horizontal position. The liquid used is a mixture of water and glycerin with presentations of 0%, 10%, 20%, and 30%. This research was conducted to determine the effect of superficial gas (JG), liquid (JL) velocity and the effect of viscosity on pressure gradients. To get the pressure gradient data using the MPX system's fluid pressure sensor that can detect any pressure difference or pressure drop in a flow that is connected to a computer. The results showed that the pressure gradient is influenced by the velocity of the liquid, gas and viscosity. The influence of JL in the range of 0.033, 0.539, 0.879, 2.297 and 4.935 m / s by varying JG (0 - 66.3) m / s and JG in the range of 0.025; 9.62, 22.6, 50 and 66.3 m / s by varying JL (0.033 - 4.935) m / s experienced an increase in the pressure gradient with each increase in the value of the JG and JL varied. Viscosity also affects the pressure gradient, from the results of research data on GL 0%, 10%, 20%, and 30% by varying JG = 0.423 m / s and JL = 4.935 m / s. This shows that as the viscosity of the liquid increases, the resulting pressure gradient will increase.