This paper explores various characterizations and properties of S-pure submodules, including their relationships with other types of submodules such as extended S-pure submodules and extended S-flat modules. We investigate conditions under which extended S-pure submodules are preserved under certain operations, such as taking direct sums and extensions. Additionally, we examine examples illustrating the significance of extended S-purity in different algebraic contexts, including its implications for projective modules and flat modules. We introduce some concepts class of modules relative to a semiradical property.  Let S semiradical property and M be a module. We say that N extended S-pure submodule if there is K submodule of M such that N∩K=0 and S(M/(NÅ K))=0.    In the first part, we define a submodule S2(M) by the equality S2(M)/(S(M) =S(M/S(M) ), for any module M. A module M is called S-Goldie module if S2(M)=M. Also, we introduce the concept extended S-pure submodule. We consider the relations between the second semiradical (S-Goldie) submodule and extended S-pure submodule. In the second part, we introduce the concept of extended S-flat module. M is called es-flat module if for any epimorphism f:N→M, kerf is extended S-pure submodule in N. Also, some basic properties are investigated.