Aligning capabilities for nematic liquid crystal (NLC) using a in-situ photodimerization method on various Photo-crosslinkable Polyimide (Pl) based polymer and blending photopolymer surfaces were investigated. High pretilt angle of the NLC can be measured by obliquely polarized UV exposure on a photo-crosslinkable polyimide based polymer surface containing biphenyl (BP), decyl (de), and cholesteryl (chol) group, respectively. However, the low pretilt angle of the NLC was measured by obliquely polarized UV exposure on the blending photopolymer (Pl and cinnamate materials) surfaces. Consequently, the pretilt angle of the NLC generated on the photo-crosslinkable polyimide based polymer surfaces using the in-situ photodimerization method was higher than that of the blending photopolymers.