In order to apply REBa₂Cu₃O_y (REBCO: RE=Rare Earth) superconductor, the superconducting properties of REBCO in magnetic field should be improved. For the improvement the superconducting properties, we focused on LaBa₂Cu₃O_y superconductor. The LaBCO has the highest critical temperature (T_c) among REBCOs. On the other hand, it is very difficult to obtain high T_c LaBCO thin films because LaBCO is easily substitutes La³⁺ ions for Ba²⁺ sites and forms solid solutions which have low T_c. For this problem, we used Vapor-Liquid-Solid growth mode (VLS) in fabricating the LaBCO epitaxial films in order to prevent La/Ba substitutions. In this study, we investigated an effect of the VLS growth mode on the superconductivities in the LaBCO thin films and also studied substrates dependence of LaBCO thin films fabricated on various substrates and a buffer layer. From comparison between a VLS-LaBCO film and a conventional LaBCO film, we confirmed that the VLS growth mode was able to prevent the La/Ba substitutions. We compared superconducting properties of LaBCO thin films prepared on various substrates and a buffer layer and found that superconducting properties of LaBCO thin films was influenced by both the strain arising from the substrates and LaBCO crystallinity.