Two-phase flow is the flow that flows in a pipe at one time and area simultaneously with more than one phase or form of a fluid. Two-phase flow is the science that examines basic parameters with the simplest multi-phase flow method. The basic characteristics of the two-phase flow are: flow pattern or flow pattern map, void fraction, and pressure gradient. In the investigation of this test used a mixture of water-glycerin 40, 50, 60, and 70% to determine the pressure gradient in the capillary pipe with a diameter of 1.6 mm with a slope of 30° to the horizontal position. The pressure gradient is the decrease in the pressure of the long unity flow along the flow path. Research was conducted to determine the effect of speed from superficial velocity liquid (JL) = 0.033 - 4.935 m / s, the effect of superficial velocity gas (JG) = 0 - 66.3 m / s and the effect of liquid viscosity on pressure gradients in capillary pipes. The tools used to obtain pressure gradient data are pressure tranducer and acquisition data arduino which are connected to the test section in and out on capillary pipes. The data is in the form of analog data, then the pressure tranducer is connected to acquisition data arduino to convert digital data on a computer. Data is processed by a computer using the Microsoft Excel program. This study is to show that the pressure gradient with the greater the value of JG and JL used, the higher the pressure gradient. Increased pressure gradients in the tests conducted from three JL (0.149, 0.539 and 0.7 [m / s]) with variations in JG (0 to 66.3 [kPa / m]) have increased. Likewise, the effect of JG ranges from 0.066; 9.62 and 22.6 m / s by varying JL 0.033 - 4.935 m / s. The pressure gradient at JG = 50 m / s JL = 0.033 m / s with a viscosity of 40% showing an average pressure gradient of 18,574 [kPa / m], while the viscosity is 50%, 60%, and 70% the average pressure gradient produced 35,537; 141,899; and 156,003 [kPa / m]. Thus the test performed shows the greater the viscosity of the fluid, the greater the pressure gradient produced