Abstract: Pressure in GangZao Product Pipeline is frequently lowered to a great extent during scheme shutting down.For the long- distance oil products pipeline operated by tight line process at ordinary temperature, volume compressibility and expansibility for transported oil products exist at the different temperature and pressure, therefore, the influence of temperature on running parameter of pipeline should not be ignored in process calculation.Based on relative data of GangZao Oil Products Pipeline, the effect of temperature on oil products volume and pressure is analyzed.Results show that decrease of oil products temperature is the major cause for the pressure drawdown after shutting down.