In present study, we clarify the micro- to mesoscopic deformation behavior of semicrystalline polymer unit cell by using large deformation finite element homogenization method. Crystalline plasticity theory with penalty method for enforcing the inextensibility of chain direction and nonaffine molecular chain network theory were applied to the representation of the deformation behavior of crystalline and amorphous phases, respectively, in composite microstructure of semicrystalline polymer. The different directional tension and compression are applied to the 2- dimensional plane strain semi-crystalline unit cell model. A series of computational simulation clarified highly anisotropic deformation behavior of microstructure of semi-crystalline polymer, which is caused by rotation of chain direction and lamella interface, and manifests as a substantial hardening/softening. This anisotropy for tensile deformation is higher than that for compressive deformation.