Let R be a commutative ring with identity. We give a new generalization to prime ideals called ,-prime ideal. A proper ideal P of R is called an ,-prime ideal if for all a,b in R with ab 2 P, then a 2 P or , (b) 2 P where ,2 End(R). We study some properties of ,-prime ideals analogous to prime ideals. We give some characterizations for such generalization and we prove that the intersection of all ,-primes in a ring R is the set of all ,-nilpotent elements in R. Finally, we give new versions of some famous theorems about prime ideals including ,-integral domains and ,-, elds.