Multiplex is a set of graphs on the same vertex set, i.e. {G(V,E1),…,G(V,Em)}{G(V,E1),…,G(V,Em)}. It is a type of generalized graph to model the multiple relationships in a system with parallel edges between vertices. An important application in Network Science is to capture community structures in multiplex as a way to modularize the system. This paper is a literature review and comparative analysis on the existing communities detection algorithms for multiplex. The conclusion is that many of the algorithms deviate in the concept of multi-relational communities and the wrong choice of algorithm can deviate one from his intended concept.