Abstract: A series of tung oil mixture used in urea coating were prepared by changing the content of P resin and inorganic conditioner in the mixtures.The viscosity,viscosity index and temperature sensitivity of the viscosity for these mixtures were measured using a rotational rheometer.The effects of several factors on viscosity,such as composition of the mixture and shearing rate,were investigated in detail.The results show that there is a negative deviation comparing with the linearity plus relationship for the viscosity of the mixture prepared with tung oil and P resin.When the content of P resin is about 30%,the viscosity of the mixture is minimum.For theviscosity of the mixture tung oil and inorganic conditioner increases as the increase in content of inorganic conditioner in mixture.When the content of inorganic conditioner is smaller than 25%,the viscosity of the mixture is smaller than 500 mPa·s,When the content of inorganic conditioner is up to 50%,the iscosity of the mixture may overtake 103mPa·s.The viscosity index of the mixture decreases as the increase in content of inorganic conditioner in mixture.The temperature sensitivity index of viscosity increases when the inorganic conditioner is introduced into the mixture.The viscosity of tung oil and the mixture of tung oil and P resin((1:1)) keep nearly unchangable when the shearing rate increases.Howerer,the viscosity of the mixture of tung oil and inorganic conditioner drops remarkably when the shearing rate increases.