Thirty four coenopopulations of Platycodon grandiflorus (Jacq.) A. DC. were studied in East Zabaikalye. As a result the basic ontogenetic spectrum was made up. Dynamics of the ontogenetic spectrum was studied in the experimental plot using the example of a normal in-complete coenopopulation in the composition of the forb-sedge ( Carex korshinskyi Kom., C. duriuscula C.A. Mey., Artemisia gmelinii Weber in Stechm., Filifolium si-biricum (L.) Kitam, Bupleurum scorzonerifolium Willd.) steppe in 2003-2007.Key words: coenopopulation, onthogeny, ontogenetic states, ontogenetic structure.