Objective To investigate the serum lactate dehydrogenase (LDH),total bilirubin (TBIL)and indirect bilirubin (IBIL)and homocysteine (Hcy)levels change in megaloblastic anemia (MA)and myelodysplastic syndrome (MDS)in the differential diagnosis of the clinical application value.Methods Hitachi 7 600 automatic biochemical analyzer was applied to the determination of 40 patients with MA,30 with MDS patients and 40 healthy physical examination (normal control group)of serum LDH,TBIL,IBIL and Hcy levels,and application SPSS16.0 statistical software for data processing were retrospectively analyzed.Results Ma group of LDH,TBIL,IBIL and Hcy four biochemical index level was significantly higher than that of MDS group and normal control group (P<0.01).MDS group of LDH levels higher than normal control group (P<0.01).MDS group of TBIL,IBIL and Hcy,there was no statistically significant difference compared with normal control group (P>0.05).MA group of LDH,TBIL,IBIL,Hcy higher positive rate higher than that of MDS group,LDH and Hcy was most significant,four biochemical indexes between the two groups compared to increase the positive rate of difference was statistically significant (P<0.01).Conclusion Joint detection of LDH,TBIL,IBIL and Hcy four biochemical index level of the differential diagnosis of MA and MDS has certain clinical value.