  For each given union-closed family F of n elements and m sets, we discuss the
union-closed sets conjecture from height number of the UC family, which is a
natural parameter from lattice theory. In this paper, we call it height number
of F(n, m), recorded as H(F). we prove that for any given union-closed family
F, union-closed sets conjecture holds if its height number H(F) no more than 3
or no less than n-1. Since the height number H(F) is a positive integer which
is bounded between 1 to n. As an attempted approach and framework, if we can
prove union-closed sets conjecture holds for all possible value of H(F), then
union-closed sets conjecture is true.
