Objective：To investigate the effects of NMDA receptor on the long term potentiation（LTP） and c-fos expression induced by high frequency stimulus. in rat striatum in vitro. Methods：Both extracellular field potential recording and immunochemistry method were used in the study. Results：The results showed that LTP was inhibited by NMDA receptor antagonist MK-801（20 -滋mol／L） completely， and that activation of c-fos induced by tetanic stimulus in the same slices was inhibited. Conclusion：The present results demonstrated that NMDA receptor was involved in LTP and c-fos expression after tetanic stimulation.