[en] We have investigated vortex states in chiral helimagnet/superconductor bilayer systems under an applied external magnetic field $H_{\mathrm{a}\mathrm{p}\mathrm{p}\mathrm{l}}$, using the Ginzburg–Landau equations. Effect of the chiral helimagnet on the superconductor is taken as a magnetic field $H_{\mathrm{C}\mathrm{H}\mathrm{M}}$, which is perpendicular to the superconductor and oscillates spatially. For $H_{\mathrm{a}\mathrm{p}\mathrm{p}\mathrm{l}}=0$ and weak $H_{\mathrm{C}\mathrm{H}\mathrm{M}}$, there appear pairs of up- and down-vortices. Increasing $H_{\mathrm{a}\mathrm{p}\mathrm{p}\mathrm{l}}$, down-vortices gradually disappear, and the number of up-vortices increases in the large magnetic field region. Then, up-vortices form parallel, triangular, or square structures. (paper)