Do I need to re-send the same GRE test score if I want to apply for the same graduate program again? I applied for a master program of university X two years ago and was rejected. Then I went to another master program and now I am about to finish. I want to apply for the PhD program of university X this year, and I have no plan to re-take the GRE test. I am wondering if it is need to re-send the GRE score to the same department of the same university.
It depends on the university. Many of them don't retain materials from applicants whom they ultimately did not accept. However, their policies regarding GRE scores may differ. 

Shoot an email to the department; they should reply within a few days.