Polyamides (PAs) are one of representative synthetic polymers, which have used in a variety of industrial fields such as textiles, military equipment, and machine components etc. However, in producing process of PAs, many environmental problems have happened, because of petrochemical-derived monomers. Therefore, in this study, we report on the synthesis and detailed characterization of PA 56 as a basic research for the development of biomass-based PA 56 to replace petroleum-based PA 66. We used 1, 5-diaminopentane and adipic acid (AA) by solid-state polymerization to prepare PA 56. For the comparison, PA 66 was synthesized using 1, 6-diaminohexane and AA in the same condition. The degree of polymerization and structural characteristics of PAs were measured through gel permeation chromatography (GPC), fourier-transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). To investigate the physical and thermal properties of PAs, differential scanning calorimetry (DSC), thermogravimetric analyzer (TGA) and universal testing machine (UTM) were used.