For the determination of CCC residues samples of grains and straw of four varieties of spring wheat and oat were extracted with ethanol. CCC was purified by column chromatography with an ion exchanger and alumina as well as by TLC. After its identification by the Rf and a colour reaction on the thin layer plate a colorimetric method with dipicrylamine was used for the quantitative estimation of CCC. The recovery rate amounts to 98+/-5% for wheat grains and straw and to 80 +/- 5% for oat grains. The detection limit is at 0.1 ppm. The amounts of CCC reach in wheat grains 0.3--0.7 ppm, in wheat straw 1--7 ppm and in oat grains 0.9--3.4 ppm in the dry matter. In oat straw CCC could not be detected with this method.