Pathogenic microorganisms infecting the upper section of the vagina in majority of cases are transferred by sexual contacts, and may originate from the food system and infected urinary system. They cause a visible infection (vaginitis) or a state without visible infection rate (vaginosis). The vagina biocenosis strictly depends on the morphological structure of vagina mucous membrane and a woman's vagina physiology overruled by the hormonal situation. The biological process proceeding in the vagina mucous membrane is responsible for a permanent balance in the environment with vagina's physiological flora which is Lactobacillus acidophilus varieats vaginalis. The vagina and physiological flora environments balances may be disturbed in some periods in terms of both quantity and quality, for instance in menstrual cycle, pregnancy, puerperium, menopause, with immunological deficiencies in local and general immunity, and finally in uncontrolled chemotherapy operations. The immunological mechanisms in women's vaginas may be divided into non-specific and specific. The first ones are mainly responsible Lactobactillus vaginosis due to making the vagina environment acid and creating bacteriocines - a substance of an antibiotic character. A mechanical decortication of the epithelium cells, generating of a mucus and phagotycosis processes supplement that sort of mechanisms. Generating the IgA antibodies by a mucous membrane and providing, by way of blood, ready antibodies is a sort of specific immunity having particular significance in those periods of a woman's life when no bacteriological flora is reported. In the paper biological processes in the environment of the vagina are presented.