Objective: To study the relation of bile acid levels and fetal hypoxia and brain injury in Intrahepatic Cholestasis of Pregnancy (ICP). Methods: From May. 2006 to Sep. 2006, we selected 30 cases of ICP as the study group, and randomly selected 30 cases of normal pregnant women for delivery during the same period as the control group in our hospital. Color Doppler ultrasound was used to measure the peak systolic velocity to end-diastolic velocity (S/D) and the resistive index (RI) of fetal middle cerebral artery, and the automatic biochemical analyzer be used to detect the total bile acid (BA) in maternal blood, and BA, pH as well as lactate in umbilical arterial serum; neuron-specific enolase (NSE) in umbilical artery serum was detected by ELISA. The results were analyzed and compared. Results:①The BA concentration in maternal blood and newborn umbilical artery blood of the study group was significantly higher than that of the control group ( P<0.01). In the study group, the BA in maternal and newborn blood were positively correlated ( r=0.937, P< 0.01) ;②Lactate and the NSE Concentration in newborn umbilical artery of the study group was significantly higher than that of the control group ( P< 0.01). The pH value innewbom umbilical artery and The S/D, RI value of fetal middle cerebral artery in the study group was significantly lower than those of control group ( P< 0.01); ③ In the study group, the NSE concentration was positively correlated with BA and lactate concentration in newborn umbilical artery, while negatively correlated with the S/D and RI values of fetal middle cerebral artery and the pH value in newborn umbilical artery ( P<0.01). Conclusions: There is the existence of hypoxia and brain injury in fetus of ICP. By measuring the blood flow changes of fetal cerebral artery with Color Doppler and detecting pH, lactate as well as NSE levels in umbilical arterial blood, we could early predict the fetal hypoxia and diagnose the fetal brain injury in ICP.