Hi, when I Xref the original DWG into my own DWG, all the text change size to really small!?!I´m not able to change anything in the original DWG, can I change it in some settings in my own DWG?

Only the text changes size and not any of the objects?Do both drawings share a common text style?

You can't change the text size of a xref.

Your problem may have something to do with annotative text and the annotation scales of the source & host drawings...