  For an arbitrary L\'evy process $X$ which is not a compound Poisson process,
we are interested in its occupation times. We use a quite novel and useful
approach to derive formulas for the Laplace transform of the joint distribution
of $X$ and its occupation times. Our formulas are compact, and more
importantly, the forms of the formulas clearly demonstrate the essential
quantities for the calculation of occupation times of $X$. It is believed that
our results are important not only for the study of stochastic processes, but
also for financial applications.
