Abstract: Objective: To evaluate the toxic influence of the change of T/C on the nervous system of neonatal guinea pigs with hyperbilirubinemia.Methods: Thirty neonatal guinea pigs at 5 to 7 days of age were randomly divided into five equal groups:one control group and four experiment groups,were embedded electrode in cranium after anesthesia.Experiment groups were injected with crystal bilirubin(T1,100 μg/g;T2,200 μg/g),and control group with normal saline(0.5 ml),T/C were recorded and nervous systems including their behavior were observed before and after 4 h,8 h of injection.Then guinea pigs were executed and taken their brain tissue,which were observed under optical and electron microscope.Results: T/C in experiment groups:there is statistical significance between before and after celiac injection of bilirubin(P<0.01),except T1b group(P>0.05).T/C in all groups:T1(T1a,T1b)groups and T2(T2a,T2b) groups respectively compared with the control group and there is statistical significance between them(P<0.01).Conclusions: The change of T/C in hyperbilirubinemia at different concentration and time,we can forecast the injury of nerval toxicity in hyperbilirubinemia early.Sensory gating,as a measurement of cognize and attention to the brain,may evaluate and prevent the injury of brain to neonate in clinic.