[en] A determination of magnetic structures of metamagnetic PrCo₂Si₂ has been made in high fields up to 16 T by using a pulsed high magnetic field system developed by the present authors. It has been confirmed that the complicated magnetic structures in high fields obtained by this experiment are identical with those suggested by high field magnetization measurement. The maximum field in this experiment is the highest one reported so far as the magnetic field used for the neutron diffraction experiments and it has been turned out that the pulsed field method is useful to determine the magnetic structures in high field phases. (author)