Hello
I have a so particular case of inheritance and i don't know how to map this with hibernate.

I have an objet Person that have two child objects
NaturalPerson and LegalPerson

I have to map this stuff with three tables

The problem is that person have a unique ID (numeric incremental)
and NaturalPerson and LegalPerson should manage "versions" of the same Person and because of this, that objects have a composite-id with the person code and the version date.

How can i map this inheritance if the parent object have just one key and the child object have two?...

it's not because your db has a composite id that your business object must has the same id...
you can code a business method that set the date property and use version when setting the "single" id.
You might some workaround but don't "focus" on that, this is only a business problem.