Abstract. We investigate the order of vanishing of p-adic L function at s =
0 via class ¯eld theory. Our investigation gives rise to relations with Tate
modules of number ¯elds and connections to conjectures of Gross and Coates-
Lichtenbaum as well as a question of Kato. We reduce the conjecture to the
study of universal norm elements and norm comparable elements over the
cyclotomic Zp-extension. Based on examples and technical evidences, we are
lead to a conjecture on the Galois invariants of Tate module which is stronger
than the Gross conjecture.