on primary isolated submodules

Let l be a left module over a ring s with identity. in this paper, the concept of primary isolated submodules is introduced. we look for relations between this class of submodules and related modules. a number of facts and characterizations that concern is gained. the aim of this work is to introduce and study the primary isolated submodules as a generalization of isolated submodules. a submodule a of l is primary isolated if for each proper b of a, there is a primary submodule c of l, b ⊆ c but a ⊈ c. some properties are gained and we look for any relationship between this type of modules and other related modules.