The main task in annual sowing of agricultural crops is to create optimal largest supply area for each plant. The nature of the seed placement on the field is determined by the following indicators work of sowing machines. This indicators are gen-eral sowing instability, irregularity of sowing seeds between rows, imprecision in placement seeds along the entire series. Usually we assume that the performance indicators of sowing machines do not correlate with each other. But this assumption is quite rough, because in practice most of the change in the index entails a change in the value of another parameter. In order to describe the influ-ence of one index to another parameter proposed to use the structural form of the model. The struc-tural form of the model is the system in which the dependent variables can be located in the left and on the right side of equation. Therefore these fig-ures are in some endogenous and exogenous equations in other. There is a possibility of using the structural shape of the model. This is done in order to identify qualitative indicators of sowing ma-chine on the example of a grain drill "Klen-6" on the basis of experimental data. Using this structural form of the model will allow building a model of the functioning of a particular type of seed grain sowing machine.