This is too vague. It could be leaking oil from anywhere.
First off, are you sure it's oil?
Secondly, where does it appear to be leaking oil from?
Third, you should use some UV dye in the oil, let it run for a bit, then use a UV light with the lights off. Shine the UV light all over the top and bottom of the engine. Wherever you see UV light is where it's leaking oil from. This is the easiest way to pinpoint the exact location of a leak as oppose to guessing.