This study was designed to determine the effects of sample collection and storage conditions on the measurement of ghrelin in bovine plasma samples.Two RIA systems for the measurement of acyl ghrelin and for total ghrelin in bovine plasma were carried out.[1] The results showed the levels of both forms ghrelin gradually decreased when heparin in blood was added at the dose of 8,4 and 0 IU/mL blood(P<0.05),but the levels of both forms ghrelin were no difference when the dose of heparin at 16 and 8 IU/mL blood(P>0.05).