  Numerical simulation on nuclear collisions are performed using the
canonical-basis time-dependent Hartree-Fock-Bogoliubov theory (Cb-TDHFB) in the
three-dimensional coordinate space. Comparing results of the Cb-TDHFB and the
conventional time-dependent Hartree-Fock (TDHF) calculations, we study effects
of the pairing correlation on fusion reaction of $^{22}$O+$^{22}$O,
$^{52}$Ca+$^{52}$Ca, and $^{22}$O+$^{52}$Ca, using the Skyrme SkM$^*$
functional and a contact-type pairing energy functional. Although current
results are yet preliminary, they may suggest that the pairing correlation
could hinder the fusion probability at energies in the vicinity of the Coulomb
barrier height. We also perform a calculation for heavier nuclei,
$^{96}$Zn+$^{124}$Sn, which seems to suggest a similar hindrance effect.
