In this paper,by means of the set of some prime ideals of an R0-algebra M,the irreducibly representational theorem of an R0-algebra M is characterized.Namely,we proved that an R0-algebra M has an irreducible representation if and only if there exists φP with ∩φ={0} such that [M]φ is atomic,where P is the set of all prime ideals of the R0-algebra M.