The quantitative analysis conditions for SEM-EDS have been set for oxidized materials such as glass and glaze on pottery. The 52 standard samples (SPI, USA) of which the chemical compositions are known were used for the first standard materials. From these first standard materials X-ray spectrums were obtained and quantification profiles were made of each chemical element. Then, from the second standard materials (JOEL, JAPAN) for which the EPMA was used, different positions of the glass sample were analyzed, after which an average value for the composition of standard materials was established. The results obtained in these analyses and the analyses from different analytical instruments, using the student t-test, which is a statistical method, and the quantification results were compared. Methods have been studied, which may demonstrate the existence of weathered layer on the ancient glass and, based on such demonstration, provide quantitative analysis that is close to the original composition of the glasses. Results indicated that there was approximately a 10% difference in the total amount between the weathered layer and unweathered layer. It seemed to be caused by alkali elements (Na, K) which had been hydrated by the water in the soil, and by hydrogen that had not been analyzed by EDS. Accurate judgement was impossible with the Soda-Lime or Potash-Lime glasses when only the surface layers were analyzed with EDS. Sodium and Potassium had been dissolved and therefore existed less than the actual contents. When the results of the analysis indicate the total is within the 90% range, if a normalized result is used, then a completely different result would be obtained. The results of an analysis of glass beads exvavated at Maha-ri, Pongtam, myun, Hwasung-gun, Kyonggi Province indicated the following. Except for a few of the beads, which were blue colored, the rest of the glass was from the Soda family. These results indicated a difference from the Potash glass, which is known to have been influenced by the Chinese Han Dynasties (BC 206-AD 220), that has been frequently excavated in South Korea's central region. Scientific analysis and research on glass, the characteristics of remains, the relationships between glass and objects found at the same site and epochal and regional classification should all be undertaken. From this research, much more reliable data on the origins of glass and various remains can be presented.