[Obejective]To observe the antipyretic effect of total organic acid in Thladiantha Dubia fruit(TOATDF),and explore its mechanism. [Methods]The rat fever models were established by the injection to SD rats with LPS 100 μg /kg of their body weights. The model rats were randomly divided into TOATDF 300,150 and 75 mg /kg dosage groups,aspirin 150 mg /kg control group and model group,and another10 rats were taken as normal control. Body temperature was measured once every one hour after the medicine,and for six times in a row.ELISAE method was used to determine the expression level of PGE2,TNF-α and IL-β in serum and that of PGE2 in cerebrospinal fluid. [Results]The average body temperature of rats at any point of time in TOATDF 300 and 150 mg /kg dose group of rats was lower than that of rats in the model control group(P < 0. 05 or P < 0. 01); temperature of rats in the 75 mg /kg group 2- 5 h after the drug was significantly lower than that of rats in the control group(P < 0. 05); temperature of rats after 1- 5 h in aspirin group after drug was obviously lower than that of rats in the control group. The expression level of TNF-α,PGE2,IL-β in serum and that of PGE2 in cerebrospinal fluid in each dosage group were significantly lower than that in model control group( P < 0. 05 or P < 0. 01),but higher than that in the normal control group( P <0. 05). [Conclusions]TOATRF has significant antipyretic effect with dose-dependent. Its the antipyretic effect is related to the inhibition of the increase of PGE2,TNF-α and IL-β induced by pyrogen. [Obejective] To observe the antipyretic effect of total organic acid in Thladiantha Dubia fruit (TOATDF), and explore its mechanism. [Methods] The rat fever models were established by the injection to SD rats with LPS 100 μg / kg of their body weights . The model rats were differentiated into TOATDF 300, 150 and 75 mg / kg dosage groups, aspirin 150 mg / kg control group and model group, and another 10 rats were taken as normal control. Body temperature was measured once every one hour after the medicine, and for six times in a row. ELISA method was used to determine the expression level of PGE2, TNF-α and IL-β in serum and that of PGE2 in cerebrospinal fluid. [Results] The average body temperature of rats at any point of time in TOATDF 300 and 150 mg / kg dose group of rats was lower than that of rats in the model control group (P <0.05 or P <0.01); temperature of rats in the 75 mg / kg group 2- 5 h after the drug was significantly lower than that of rats in the control group (P <0.05); tempe rature of rats after 1- 5 h in aspirin group after drug was obviously lower than that of rats in the control group. The expression level of TNF-α, PGE2, IL-β in serum and that of PGE2 in cerebrospinal fluid in each dosage group were significantly lower than that in model control group (P <0.05 or P <0.01), but higher than that in the normal control group (P <0.05). [Conclusions] TOATRF has significant antipyretic effect with dose-dependent. Its the antipyretic effect is related to the inhibition of the increase of PGE2, TNF-α and IL-β induced by pyrogen.