This study was aimed to examined effect of Januvia treatment on methionine synthases Meth and cystathionine B- synthase (CBS) in Iraqi patients type2 without treated and another group who taken Januvia treated in addition to diabetic patients with complication without treated with Januvia Also, to found the relationship between these parameters with BMI, FBS, HbA1C and Insulin levels. Firstly, the blood sampling date for this research between December and February 2019 - 2020. Blood sampling was withdrawn from 8:00 to 10:00 in the case of fasting of all substances . five milliliters of venous blood were collected by means of an antecubital venipuncture divided into two parts, one of which (2ml) was put in a tube containing anticoagulant factor Ethylene Di-amine Tetra acid [EDTA] to measure HbA1C by means of an I instrument, while another portion (3ml) of blood was put in a plane tube t0 collect sera and storage in the freezing -20°C to evaluate glucose, methionine synthase, cystathionine B- synthase and insulin. From this study, we concluded Januvia treatment didn't give the target for decrease blood sugar to prevent developing complication so we show non-significant correlation between classic parameters when compared with Meth and CBS exactly for group who treated with Januvia the attended for those medication didn't preferred for treated and prevent complication development like ischemic heart disease.