Corrosion of steel pipeline can form numerous leaks, reduce service life of pipeline, and make large losses. Use of nonmetallic pipeline can solve the problem. Glass fiber reinforced plastic pipeline is nonmetallic pipeline. It can be installed conveniently, would not corrode in electrochemistry environment, and its service life is very long. So, it is widely used in many fields such as petroleum, city water supply, waste water processing, etc. In the paper, hydraulic calculations of pipeline are researched, and frictional resistance losses of water in glass fiber reinforced plastic pipelines with different diameters are measured, and relation curves between losses and Reynolds number are obtained. Based on experimental data, errors between experimental values and calculation values of formulas for hydraulic calculation are analyzed. The formulae to calculate the frictional resistance in glass fiber reinforced plastic pipeline are recommended. The researches in this article are very important for the reasonable design, effective management and the economic operation of glass fiber reinforced plastic pipeline.