There's a way to remove the limitation of 65000 on new unity 3?

I want put an object that have more than 65000 but an error says me "Meshes may not have more than 65000...."

You can't have more than 65000 vertices per mesh. Break the mesh up into more than one piece, which you would want to do for performance reasons anyway--you wouldn't want to have such huge meshes being uploaded when you can only see part of them at any one time. Also ask yourself if you really need that many vertices or if you could optimize the mesh more.

Try Using the MultiRes or try breaking the MESH up and importing as smaller pieces.

Why do you want to do that?

It is better to have a larger number of smaller models that make a big scene object. Viewing frustum culling and occlusion culling will have no effect if you make your whole scene from a single mesh.