Abstract: Objective To discuss onefold homocystinemia caused by nutritional megaloblastic anemia and its relationship with cardiovascular disease. Methods The case control study was conducted among case group(23 patients with nutritional megaloblastic anemia), control group Ⅰ(23 healthy persons)and control group Ⅱ(23 persons who recovered from nutritional megaloblastic anemia). Results The difference on homocystine concentration in plasma between case group and two control groups had statistical significance(P＜0.01), but the difference on cholesterol concentration in plasma had no statistical significance(P＞0.05). The difference on homocystine concentration in plasma between two control groups had no statistical significance(P＞0.05). Conclusion The patients with nutritional megaloblastic anemia usually have onefold homocystinemia, which could not cause cardiovascular disease.