  For a cellular algebra $\A$ with a cellular basis $\ZC$, we consider a
decomposition of the unit element $1_\A$ into orthogonal idempotents (not
necessary primitive) satisfying some conditions. By using this decomposition,
the cellular basis $\ZC$ can be partitioned into some pieces with good
properties. Then by using a certain map $\a$, we give a coarse partition of
$\ZC$ whose refinement is the original partition. We construct a Levi type
subalgebra $\aA$ of $\A$ and its quotient algebra $\oA$, and also construct a
parabolic type subalgebra $\tA$ of $\A$, which contains $\aA$ with respect to
the map $\a$. Then, we study the relation of standard modules, simple modules
and decomposition numbers among these algebras. Finally, we study the
relationship of blocks among these algebras.
