Abstract. Scientists have been researching for a long time, where they have found evidence of a connection between “Lactobacillus - Caries”. According to the results of some countries, the qualitative and quantitative composition of lactoflora of the oral cavity is already known in the norm and case of diseases caused by disbiotic conditions of the mouth. This article presents the results of the quantitative and qualitative composition of oral lactoflora of women of fertile age, the state of biological properties of each particular representative and their impact on cavities formation, which can explain the microbiological etiology of cavities. Each of the following indicators was statistically processed and compared with the results of foreign countries.