The rhcological properties of cow's milk and cervical mucus arc studied in this paper and the macroscopic rheological models of this two living fluids are obtained. On the basis of following the cow's estrous and gestational period, and investigating the effect of milk's components and cow's health state on the rheological properties. we are trying to set up two kinds of quantitattvely rheological standards used for i) determining the cow's estrus and early gestation, ii) verifying the quality and the nourishing value of milk for development of the fast-testing instrument of the quality of milk, respectively.