Abstract: Multiphase pump and multiphase pipeline have their own performance curves, respectively. A two-screw multiphase pump conveys the mixture of oil and gas in a multiphase pipeline with ten kilometers long. The performance characteristics of this boosting transportation system were investigated under different pipe diameters, different gas fractions and different fluid viscosities. The results have shown that diameter, gas fraction and fluid viscosity have slight impact on flow rate of this boosting system, but have remarkable influence on pressure drop of this system.