The results of the researches on the ivestigation of the principle of action of technical system of entering into the soil of working liquids of biologically active agents are presented. Considered process is shown in the form of difficult system including the subsystems of dispensing and distribution of these liquids by the num-ber of sowing working bodies for processing of seeds (mechanized inoculation) along with crops. Thus dozing and distributing devices available now serving for enter-ing into the soil of liquid forms of bacterial preparations do not provide demanded parameters of considered technological process regarding the uniformity of their distribution on sowing working bodies. The essence of the solution of this problem is defined by finding out the principle of action of technical system for uniform distri-bution of working liquids of biologically active agents. Functioning of this system is presented in the form of counting the effects with the most admissible number of levels, equal to five. Thus required principles of action of the system consist of the effects which form the chains connecting each of two next tops of the count. The ex-pediency of using pressure head system of distribution of working liquids and their dispensing by the number of sowing working bodies for processing (inoculation) of seeds at the time of seeding is proved. The interrelation of distribution of working liquids of biologically active agents on sowing working bodies with the existence of their high-speed stream in the distributor batcher was established. The principle of action of the system as set of physical effects which coordinated manifestation pro-vides performance of its functions was defined. The statement of material is based on the application of combinatory method with using algorithm of the combi-nation of effects.