The ordering process of nematic liquid crystal (LC) during evaporation onto silica substrate was investigated. The optical second-harmonic generation and polarized absorption measurements were employed to determine the orientational order parameters S(1) and S(2). A sudden increase of S(1) was observed during the first layer deposition while S(2) gradually increased. Interestingly, S(1) was nearly constant after the completion of the first layer deposition, while S(2) was similar to that in the first layer deposition. The results suggest that spontaneous orientational ordering process is induced during the first monolayer formation.