5,10-Methlenetetrahydrofolate reductase (MTHFR) is one of the most important enzymes for folic acid metabolism. This protein's gene is mapped on chromosome 1, which is located at the end of the short arm (1p36.3). MTHFR enzyme plays a key role in cell metabolism including folic acid and nucleotide synthesis (DNA, RNA). Polymorphism is also a factor in biodiversity, and is different according to ethnic heritage and racial. The 677 C>T is also MTHFR polymorphisms that decrease MTHFR enzyme activity. The aim of this study is to compile studies are associated with MTHFR C677T polymorphism. PUBMED, Turk Biochemistry and Jornal of Clinical & Experimental Investigations were searched to develop an investigatory pursuit strategy. MTHFR, Turkish population, 677 C>T and polymorphisms were key words including "MTHFR", "Türk popülasyonu: Turkish population", "677 C>T" "polimorfizm: polymorphism" used to focus the search. The literature review included all published relevant Turkish population and MTHFR polymorphisms for that all of study. The data of selected polymorphism for Turkish population was listed in tables for easy access and retrieval.