Objective To study the Research of clinical with homocysteine (Hcy) enzymatic cycling assay Methods Performance characteristics such as precision, linearity,interference testing of the kit were evaluated respectively according issued by the National Committee on Clinical Laboratory Standards (NCCLS).Results The CVs of within-run at low are 3.45%, CVs of within-run 3.78%.. The linear range is 0-50.0 μmol/L.When the concentration of conjugated bilirubin is at 20 mg/dl or chyle at 1.2% or ascorbic acid at 30 mg/dl, produced interference deviation is less than 4%.And the 150g/L of hemoglobin concentration produced less than 5.2% interference deviation.Conclusion Performance of precision, linearity and interference testing of the homocysteine assay kit produced by JiuQiang Company can fulfill the requirements of clinical laboratory.