Nitric oxide (NO) is an important diffusible neurotransmitter, which also has neurotoxicity when it is overproduced. To investigate whether electro-acupuncture (EA) could inhibit the excessive NO release during cerebral ischemia, we detected NO directly by our self-made NO sensitive electrode. The electrode was placed into rat striatum after transient middle cerebral artery occlusion. NO level was significantly increased upon the onset of ischemia and reperfusion. EA apparently antagonized the ischemia-elicited rise of NO, although it could not suppress the NO level to baseline. The results indicated that EA might inhibit directly the elevation of NO following cerebral ischemia.