Thermal, structural and morphological characteristics were investigated in the unpoled and poled polymer/organic low weight molecule systems, that is. p-nitroaniline(p-NA) and 2-methyl-4-nitroaniline (HHA)/poly(ethylene oxide) (PEO) films. Good P-HA/PEO and HHA/PEO films could be obtained from the mixtures having 50% p-NA or less. and the films containing 30% P-NA or less could be drawn. Differential scanning calorimetric measurements showed not only two strong melting peaks due to the melting of P-NA and PEO crystals but also a weak melting peak due to the interaction of two components. p-NA and MNA crystals were observed to have a short bar structure, whereas p-NA/PEO films were observed to have an entangled structure. Poling of P-HA/PEO films caused a good reorientation of p-HA crystals observed with the scanning electron microscope but such a phenomenon was not shown in the MNA/PEO films. A significant change of X-ray diffraction peaks appeared for the poled P-HA/PEO films.