The joint symposium of the 5th International Symposium on Polymers Materials Science (ISPMS'12) and the 8th Osaka University Macromolecular Symposium (OUMS'12) was held on November 10th and 11th, 2012 at Osaka University in Toyonaka, Japan. Polymer materials are industrially so important that applied polymer science is often more valued than pure polymer science. However, the pure and applied sciences should be balanced. Recent years, chemical structures of polymer materials become more complex to gain good performance and various functions, which makes difficult to characterize their molecular structures and to understand their properties from the molecular level. The development of the pure polymer science in parallel to the applied polymer science is requisite to overcome those difficulties. Therefore, the purposes of this joint symposium are (1) the interaction between the pure and applied polymer science, (2) the encouragement of pure polymer science, and (3) the education of graduate course students of the polymer science major.