This M.Sc. thesis is based on the following paper • Yasser Ibrahim,Mohamed yousif, Dual-square-free modules, Communications in Algebra 47.7 (2019): 2954-2966. ., Dual-square-free modules, Communications in Algebra 47.7 (2019): 2954-2966. This study seeks to investigate dual-square free (DSF) modules. ModuleM is called DSF ifM has no proper sub-modules of A and B withM = A #43; B and M A #24;= M B . Every summand of DSF sub-module is a DSF module. Furthermore, this set of modules is closed under homomorphic images. ModuleM is distributive iff each sub-module ofM is DSF. DSF maximal sub-modules are entirely fully-invariant. Particularly, a ringRis a right DSFR-module iffRis a right quasi-duo (i.e., any maximal right ideals are two-sided). On the other side, every DSF module is Dedekind finite. IfM possesses the finite-exchange property, thenM has the finite property and EndR(M) ring has stable 1 range. Ultimately, it is demonstrated that every DSF module likeM possesses the finite-exchange property iffM is clean iffM has the full exchange property.