  Using the idea of the penguin box expansion we find an analytic expression
for epsilon'/epsilon in the Standard Model as a function of m_t, m_s(m_c) and
two non-perturbative parameters B_6 and B_8. This formula includes
next-to-leading QCD/QED short distance effects calculated recently by means of
the operator product expansion and renormalization group techniques. We also
derive an analytic expression for the upper bound on epsilon'/epsilon as a
function of |V_cb|, |V_ub/V_cb|, B_K and other relevant parameters. Numerical
examples of the bound are given.
