Special technology of cultivation in optimal con-ditions is necessary for industrial cultivation of a tea mushroom. To find such conditions it is necessary to study kinetics of metabolic processes course in cultural liquid which chemical composition con-stantly changes with time. Hence, its physical properties will also change. All this cannot but af-fect the speed of course of biological processes. As experiments show, the development of a mush-room can be divided into two stages. The first stage is characterized by the sinking of seeding hinge plate of a mycelium brought in a nutrient medium and the development of a mushroom under a liquid layer. But as oxygen is necessary for the course of biological processes, during the initial period the mushroom consumes oxygen which is in cultural liquid in the dissolved state. Kinetics of oxygen concentration change in liquid and acidity gives the possibility to estimate the duration of the first stage and the speed of development of a mushroom dur-ing this period. The second stage begins with the moment of emersion of seeding culture and the formation of a continuous film on the surface of liquid of a new mushroom then the diffusion of oxy-gen from air on liquid environment becomes difficult (perhaps, stops absolutely), and oxygen consump- tion by a mushroom occurs through its surface ad-joining to air. On the basis of pilot studies it is shown that the formation of acid composition of cultural liq-uid of a tea mushroom has two stages. Transition from one stage to another can be determined by kinetics of concentration change of the oxygen dis-solved in liquid and its pH. The equation of the mathematical model which is adequately reflecting the course of biological processes and allowing pre-dicting it outside experimental conditions is chosen.