Objective：To prepare adult rat hippocampus slices for whole-cell patch clamp recording and to observe the electrophysio－logical properties of hippocampus pyramidal neurons. Methods：Adult male or female SD rats of 200 g in weight were selected and were narcotized by 10% chloral hydrate intraperitoneal injection. The limb was fixed，chest was cut open and inferior vena cava was clamped in all the rats. After cardiac perfusion by 0 ℃ slices liquid，the whole brain was removed and placed in 0 ℃ slice liquid for 3 min，then chopped into 350 μm thickness. The brain slices were transferred to 37 ℃ preheated artificial cerebrospinal fluid for 1 h and then transferred to 23 ℃ for 30 min. The neuronal morphology of brain slices were observed by using inverted phase contrast microscope and infrared differential interference phase contrast microscopy. Electrophysiological properties of brain slices neurons were recorded by whole-cell patch clamp. Results：Good gloss，stereoscopic and obvious neurite pyramidal neurons were observed in hippocampal CA1 region，which were easy to sealing. With the application of patch clamp technique，the changes of the currents and action potential of pyramidal neurons in CA1 region were recorded by the whole-cell patch clamp. Conclusions：The adult rat brain slices prepared by this method can withstand the damage caused by ischemia and hypoxia in vitro，remain electrophysiological properties and adapt to the whole-cell patch clamp recording.