Taxonomy includes collection, identification, naming and ordering of specimens into a system of words consistent with any kind of relationships among them, the study of literatures and analysis of variations shown by the specimens and finally the publication of data. Practical reasons for the degree of stability-even for a relatively short period of time are: for teaching purposes at advanced levels and for the benefit of many non-protozoolists. The eimeriid coccidia are one of the more controversial groups of protozoa. The problems of describing different species within family Eimeriidae Minchin, 1903 are due to their abnormal phenotypic and phylogenetic characters, occurrence in abnormal hosts with different lifecycle patterns. The basis of classification of the genera under this family includes the Phenotypic and Phylogenetic characters and the lifecycle of parasites and data of their hosts. I have updated the information of classification system given by the Society of Protozoologists (Lee JJ, Hutner SH, Bovee EC and Upton J, 2001. The Illustrated Guide to the Protozoa, 2nd Edition. Allen Press, Lawrence, KS) and online materials by Duszynski DW, Couch L and Upton SJ, Supported by NSF-PEET DEB 9521687. In this review, I have focused on seventeen true species and seven pseudospecies with the information of their synonyms, oocyst formula, generic characters, and total number of named species, type species and type host. Keywords: Eimeriidae; Genera; Phenotypic; phylogenetic; pseudoparasitism; Redescription. DOI: 10.3126/ijls.v4i0.3285International Journal of Life Sciences Vol.4 2010 pp.26-47