Abstract: Tempeture sensors were installed in the grease container of a centralized lubrication system for vehicle chassis，and pressure transmitters were installed at the beginning and the end of the main tube.The effect of ambient temperature on operating pressure of grease lubrication system was investigated in this paper employing the virtual instrument technology.The results revealed that the peak pressure values at the beginning and the end of the main tube as well as their differential pressures were increased with raise in grease temperature.The maximum peak pressure at the beginning and the end of the main tube occured when the ambient temperature was about 25℃ and 10℃ respectively.The peak pressure values at the beginning and the end of the main tube showed decreases along with temperature increasing remarkably at higher temperatures.The residual pressure at the beginning of the main tube followed a variation pattern similar to that of temperature，but at the end point the temperature′s effect on the residual pressure was not significant.