A biological testing synthetic heterocyclic compounds – perchlo- rates (thio)pyrylium differing nature of the heteroatom (O,S) and alternate character (CH3, Cl, OCH3, С6Н5) in the cation halkog- enopyrylium. The objects of the study were the seedlings of spring wheat Triticum aestivum L. To assess the physiological activity of the test compounds used analysis of morphometric parameters and quantitative content of seedling photosynthetic pigments in the leaf lamina. All of heterocyclic compounds have a stimulating effect on the growth of the first leaf sheath. Positive effects of test compounds on the growth of the leaf lamina is less pronounced. In a number of cases was observed inhibition of growth of the leaf lamina. Despite the different effects of heterocyclic compounds on growth of parts of the first leaf, significant differences in the length of the first sheet of the experimental and control plants was observed. Analysis of growth rate showed that the presence of compounds of the oxygen atom as the heteroatom, resulting reduction of the growth period of leaf lamina. The effect of the test substances on the quantitative composition of photosynthetic pigments in the lamina of the first leaf. The action of the test solutions (with some exceptions) increases the ratio of chlorophyll a/b. Determination of quantitative content of chlorophyll a and b in the lamina suggests that the inhibitory effect of the compounds on the and chlorophyll b and the stimulatory effect on chlorophyll a is associated with the presence of O as a hetero atom and Cl as a substituent. The test compounds have positive effects on the root-maintenance and the length of the root system of seedlings. The greatest stimulatory effect on the length of the root system of the seedling have a concentration 10-12М compound having S as heteroatom. Solutions of certain concentrations of heterocyclic compounds with similar substituents in the cation, have an inhibitory effect on the growth of the main root seedling, however, the total length of the root system does not differ from the control values. Analysis of the results leads to the conclusion that the tested synthetic heterocyclic com- pounds – perchlorates (thio)pyrylium have regulatory activity. Laboratory research can serve as a basis for further studies the physiological properties of these compounds.