  We study Dirichlet forms and Laplacians on self-similar sets with overlaps. A
notion of "finitely ramified of finite type($f.r.f.t.$) nested structure" for
self-similar sets is introduced. It allows us to reconstruct a class of
self-similar sets in a graph-directed manner by a modified setup of Mauldin and
Williams, which satisfies the property of finite ramification. This makes it
possible to extend the technique developed by Kigami for analysis on $p.c.f.$
self-similar sets to this more general framework. Some basic properties related
to $f.r.f.t.$ nested structures are investigated. Several non-trivial examples
and their Dirichlet forms are provided.
