Evaluation on aucubin accumulation in different ecotypes of plantain (Plantago sp.)” was carried out on on different ecotypes of plantain collected from Mongolia and Vietnam. The results showed that: (i) the amount of aucubin had been increased together with the growth stages. Minimum level of aucubin of P. depressa was found in vegetative stage (1.66 mg/g), maximum in fruiting stage (12.46 mg/g); (ii) all of ecotypes of Plantago sp. varied in their aucubin content. In addition, aucubin content of Mongolian ecotypes was higher than those of Vietnamese ecotypes’; and (iii) the geo-ecological conditions (Vietnam and Mongolia) had affected significantly on the aucubin content in different ecotypes. P. depressa contains higher amount of aucubin than P. major. The highest aucubin constituent is on P. depressa ecotype which collected in Middle Khalkh dry steppe, Mongolia (21.87 mg/g) and the lowest on P. major in Thanh Hoa-Vietnam (2.08 mg/g).