The complex of holmium with L-histidine has been isolated from solid state. The structure of the complex was determined by the elemental analysis, thermal decomposition, IR spectral and electrical conduetivity methods. The complex have the formula [Ho(His)3]Cl3.5H2O. Biological activity of the complex was indicated. At the concentration of trom 30 ppm to 240 ppm, the complex has influence on inhibits sprout and maize development, the inhibits is increased according to the concentration. The complex has inhibiting capacity which seem to be better than of central ion but to be worse than of ligand.