  The specific angular momenta ($j_t$) of stars, baryons as a whole and dark
matter haloes contain clues of vital importance about how galaxies form and
evolve. Using a sample of 70 spiral galaxies, we perform a preliminary analysis
of $j_t$, and introduce a new quantity, e.g., areal density of angular momentum
(ADAM) ($j_t~M_\star/4R_d^2$) as an indication for the existence of jet in
spiral galaxies. The percentage of spiral galaxies having jet(s) shows strong
correlation with the ADAM, although the present sample is incomplete.
