Abstract In order to study molecular mechanisms of contact guidance of neurites, dissociated culture of adult mouse dorsal root ganglion (DRG) cells was performed for 6 species of plastic plates different in monomer compositions. Microstructures (grooves of 5 10 μm wide and 1 μm deep) were grafted on the plates so as to guide neurite growth in their axial direction. Neurites were longer and more oriented on plates with larger water contact angle. The distribution of neurites was uneven between grooves and steps of the microstructures, exhibiting a bell-shaped curve in relation to the water contact angle of the plastic. These indicate that hydrophilic properties of the plastic plate surface, due to the presence of bisphenol-A and tricyclodecanyl units, are crucially involved in the elongation and orientation of neurites.