  In this paper, we have studied tunneling effect of the spin-2 Bose condensate
driven by external magnetic field. We find that the population transfers among
spin-0 and spin-$\pm1$, spin-0 and spin-$\pm2$ exhibit the step structure under
the external cosinusoidal magnetic field respectively, but there do not exist
step structure among spin-$\pm1$ and spin-$\pm2$. The tunneling current among
spin-$\pm1$ and spin-$\pm2$ may exhibit periodically oscillation behavior, but
among spin-0 and spin-$\pm1$, spin-0 and spin-$\pm2$, the tunneling currents
exhibit irregular oscillation behavior.
