Objective: To investigate the effects of kudzuvine root on 3 kinds of brain evoked potential in patients with diabetes mellitus type 2 (DM2).Methods: Forty-six cases of DM2 were randomized into two groups: the control group and the treatment group

they were respectively treated orally with 50 ml of normal saline or 50ml of kudzuvine root decoction containing kudzuvine root 0.4 g/ml. The short latency somatosensory evoked potential (SSEP)

brainstem auditory evoked potential (BAEP) and visual evoked potential (VEP) in patients were measured before and 40 min after treatment.Results: (1) SSEP in the control group was not changed significantly before and after taking normal saline (P>0.05)

while in the treatment group there appeared a significant delay in peak latency (PL) of N13 wave (N13PL) and a significant shortening in N20PL and interpeak latency (IPL) between N13 wave and N20 wave (N13-N20 IPL) after kudzuvine treatment (P<0.05 orP<0.01). But the difference of various parameters of SSEP between the two groups was insignificant difference (P>0.05). (2) BAEP in the control group was not changed significantly after treatment (P>0.05)

while in the treatment group I-III IPL and I-V IPL were significantly shortened

showing significant difference as compared with those in the control group (bothP<0.01). (3) VEP in the control group was not changed significantly after treatment (P>0.05)

while in the treatment group the amplitude of P100 wave increased obviously (P<0.01). But the difference of various VEP parameters between the two groups was not significant statistically after treatmentP>0.05).Conclusion: Kudzuvine could shorten the latent period of brain evoked potential and the central transmission time

increase the amplitude of cortex wave and turn it back to normal

thus to effectively protect and accommodate the brain function in patients with DM2.