Rectangular networks of rat hippocampal neurons have been produced on microelectrode arrays (MEAs). The crossing points of networks were located at the recording electrode sites by aligned microcontact printing (μCP) technique. Polydimethysiloxane (PDMS) stamp was fabricated to print fine poly-L-Iysine (PLL) patterns of 2μm-width lines for neurites and 20μm-diameter circles for cell bodies. Different densities of neurons were applied on the PLL-stamped MEAs to find how a low density of neurons still has the functional connectivity. From the neural network applied with a density of 200 cells/mm2, we could observe signal propagation among spontaneous activities. Electrical responses were also evoked by 200μA current pulse stimulation with 50μs pulse width. Immunocytostaining was employed to identify dendrites, synapses, and nuclei in the patterned neurons.