It was found that alkylating amino-nitropyridine was able to crystallize epitaxially in a matrix of polyethylene, as laid its alkyl chain along the extended chain axis of polyethylene even in case of such short alkyl chain as carbon numbers of 12. From the X-ray diffraction patterns, the infrared dichroism and the optical second harmonic generation of the drawn mixture, one of the possible models on its epitaxy structure has been deduced. The triclinic unit cell and the molecular packing having a center of symmetry were proposed for DANP and OANP crystals in a matrix of highly oriented polyethylene.