  The principal filtration of the infinite-dimensional odd Contact Lie
superalgebra over a field of characteristic $p>2$ is proved to be invariant
under the automorphism group by investigating ad-nilpotent elements and
determining certain invariants such as subalgebras generated by some
ad-nilpotent elements. Then, it is proved that two automorphisms coincide if
and only if they coincide on the -1 component with respect to the principal
grading. Finally, all the odd Contact superalgebras are classified up to
isomorphisms.
