  Three topics about monopole dynamics after abelian projection are reported.
The first is the new and detailed analyses of $SU(2)$ monopole action obtained
after the block-spin transformation on the dual lattice. The $b=na(\beta)$
dependence for all couplings are well fitted with a universal curve. The
distance dependence of the couplings is well reproduced by a massive propagator
with the mass $m=0.8$ in unit of $b$. The second is the $SU(3)$ monopole action
recently obtained. The third is new interesting gauges showing abelian and
monopole dominances as in the maximally abelian gauge.
