We studied the control of pretilt angles for homeotropic aligned nematic liquid crystal (NLC) on SiOx thin film surface by $45^{circ}$ evaporation method with electron beam system. The uniform vertical LC alignment on. the SiOx thin film surfaces with electron beam evaporation was achieved. It is considered that the LC alignment on SiOx thin film by $45^{circ}$ electron beam evaporation is attributed to elastic interaction between LC molecules and micro-grooves at the SiOx thin film surface created by evaporation. The pretilt angles of about $3.5^{circ}$ in aligned NLC on SiOx thin film surfaces by electron beam evaporation of $45^{circ}$ were measured. Consequently, the high pretilt angles of the NLC on the SiOx thin film by $45^{circ}$ oblique electron beam evaporation method can be achieved.