  We study the classification of D-branes in all compact Lie groups including
non-simply-laced ones. We also discuss the global structure of the quantum
moduli space of the D-branes. D-branes are classified according to their
positions in the maximal torus. We describe rank 2 cases, namely $B_2$, $C_2$,
$G_2$, explicitly and construct all the D-branes in $B_r$, $C_r$, $F_4$ by the
method of iterative deletion in the Dynkin diagram. The discussion of moduli
space involves global issues that can be treated in terms of the exact homotopy
sequence and various lattices. We also show that singular D-branes can exist at
quantum mechanical level.
