Train pricing from Marco Polo airport to Airbnb near train station on Venice island

That's because there is no train station at the airport. You cab take a bus, taxi, Alilaguna boat or private water taxi.

Didn't you just post a thread a few hours ago with this same topic? It looks like you got a number of responses so you might want to ask your question there.

Prices are included on the links I attached the the other post.