According to the kinematic viscosity of waterglycol fireresistant hydraulic fluids with different water contents measured at different temperature,the influential factors on the viscosity of waterglycol fireresistant hydraulic fluids were studied.The influence of water content and temperature on viscosity was analyzed.The power function model of temperature and viscosity,the binomial model and exponential model of water content and viscosity,and the model of water content,temperature and viscosity were established and tested.The results show that water content and temperature have a great influence on viscosity.Models established significantly fit the data well,which can be used to describe the temperatureviscosity relation,water contentviscosity relation,and water contenttemperatureviscosity relation for waterglycol fireresistant hydraulic fluids.