Abstract: In this paper,radioimmunoassay of the concentration of thromboxane B₂（TxB₂）and 6-keto-prostaglandin F_1α(6-keto-PGF_1α)in urine was described.Samples were extracted with ethyl acetate after acidification.The recovery of TxB₂ and 6-keto-PGF_1α through the extraction procedues were 95.7±1.7%（n=9）and 92.7±1.4%（n=9）,respectively.Accuracy and precision of the method were within the scope of methodology.The normal values of TxB₂ and 6-keto-prostaglandin F_1α in 76 normal individuals and individuals in different ages groups were measured.The variations in sexes and age groups were discussed briefly.