  Dipole interaction in the triplet superconductivity is studied. If the Cooper
pairs are formed by the electrons at $\mib{r}$ and
$\mib{r}+(\pm\frac{a}{2},\pm\frac{a}{2},\pm\frac{c}{2})$ in the body centered
tetragonal lattice, (in this case the line nodes run horizontally on the
cylindrical Fermi surface), the dipole energy is low when the
${\mib{d}}$-vector is perpendicular to the direction of the angular momentum of
the Cooper pairs ($\mib{l}$-vector). This result is in contrast with the dipole
energies in the ABM state of superfluid $^3$He, where $\mib{d}$-vector is
forced to be parallel or antiparallel to the $\mib{l}$-vector by the dipole
interaction. The recent NQR experiment in Sr$_2$RuO$_4$ by Ishida et al. can be
explained by this result.
