Abstract: Ginsenoside Ro decreased measures of inflammation, aging, oxidants and thrombus formation in a previous study. To measure ginsenoside Ro content in red ginseng from different years, an optimized extraction method was developed to determine ginsenoside Rg₁, Re, Rb₁ and Ro content by HPLC in 43 batches of red ginseng from different origins, growing years and manufacturers. The results indicate that the best extraction method was to ultrasonify a 1 g sample in 70% methanol for 50 min. The total running time of the optimized gradient was 50 min using a C18 core-shell column and was half the time described in the Chinese Pharmacopoeia, 2015 edition. The separation resolution of all of targeted compounds was greater than 1.6. The peak shape of ginsenoside Ro was optimal when the mobile phase consisted of acetonitrile and water with 0.1% phosphoric acid. The content of ginsenoside Ro was in the range of 0.11% to 0.43%, and the average content was 0.26%, which was higher than that of ginsenoside Rg₁ and Re. The ratio of ginsenoside Ro and Re as a threshold could be used to discriminate red ginseng from different growing years; in addition, 100%, 94.4% and 46.6% of red ginseng from six, five and four years exceeded the threshold of 1.3. Our optimized analytical method for characterization of red ginseng is convenient and shortens the assay time.