Simultaneous recording of neuroelectrical and neurochemical information of active neurons is very important for neurobiological research. This paper reports the first combination of dual mode microelectrode arrays and the corresponding integrated detection system for neuroelectrical and neurochemical recording. The microelectrode arrays incorporate planer microelectrodes, counter electrodes and reference electrodes on glass slide substrates or silicon probes, which can be used for in vitro or in vivo tests. The detection system consists of hardware and software components whose current and voltage resolutions are 10 pA and 0.6 µV, respectively. Using the dual mode detection system, neural spikes of 30µV–70µV and neurochemical oxidation currents of 30nA–600nA were simultaneously recorded from cultured neurons and brain cortex of anesthetic rat.