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Abstract: A series of metallic LaNiO3 (LNO) thin films were deposited on MgO (100) substrates by pulsed laser deposition (PLD) under the oxygen pressure of 20Pa at different substrate temperatures from 450 to 750°C. X-ray diffraction (XRD) was used to characterize the crystal structure of LNO films. θ–2θ scans of XRD indicate that LNO film deposited at a substrate temperature of 700°C has a high orientation of (l l 0). At other substrate temperatures, the LNO films have mixed phases of (l l 0) and (l 00). Furthermore, pole figure measurements show that LNO thin films, with the bicrystalline structure, were epitaxially deposited on MgO (100) substrates in the mode of LNO (110)//MgO (100) at 700°C. Reflection high-energy electric diffraction (RHEED) and atomic force microscopy (AFM) were also performed to investigate the microstructure of LNO films with the high (l l 0) orientation. RHEED patterns clearly confirm this epitaxial relationship. An atomically smooth surface of LNO films at 700°C was obtained. In addition, bicrystalline epitaxial LNO films, fabricated at 700°C, present a excellent conductivity with a lower electrical resistivity of 300μΩcm. Thus, the obtained results indicate that bicystalline epitaxial LNO films could serve as a promising candidate of electrode materials for the fabrication of ferroelectric or dielectric films. [Copyright &y& Elsevier]