This study has investigated the possible applications of ultra thin fiber reinforced plastics based on uni-directionally aligned carbon nanotube (CNT) sheet for the low thermal deformation structures like high accuracy satellite parts, antennas or optical benches. The aligned multi-walled CNT arrays with mean CNT diameters of 30 and 50 nm were grown on a base quartz substrate using chloride mediated chemical vapor deposition. The CNT sheets were produced from the CNT arrays using drawing and winding techniques. The CNT/epoxy resin prepreg was fabricated by heating a CNT sheet covered with a B-stage epoxy resin sheet. The CNT/epoxy composites with symmetrical cross-ply lamination ([90/0]s) were developed in this study. Tensile test of the CNT/epoxy composite laminates was conducted for the evaluation of mechanical properties. To create thin CNT/epoxy laminate, two layers of the prepreg were stacked with two layers of the CNT sheet. The thickness of the symmetrical cross-ply laminates was 35-50 μm. With CNT volume fractions between 15 and 35%, the composite laminates showed low strength and stiffness. The low strength and stiffness might be due to the waviness and entanglement of reinforced CNTs with large diameter. The reduction of CNT diameter led to the increase of tensile strength and the reduction of CNT volume fraction. Tensile strength of small-diameter CNT laminate was 1.5 times higher than that of the laminate reinforced by large CNT diameter. In short, to improve the mechanical properties of CNT/epoxy laminates for application in satellite structures, higher volume fraction of CNT with small-diameter CNT was required as a next step of this study.