This study was aimed to investigate the expression and clinical significance of CDX1, CDX2 and CDX4 genes in acute lymphocytic leukemia (ALL). Expressions of CDX1, CDX2, and CDX4 in 51 adult acute lymphocytic leukemia patients and 14 healthy subjects were detected by reverse transcription polymerase chain reaction (RT-PCR). The results indicated that CDX1, CDX2 and CDX4 were not expressed in 14 healthy persons and 15 CR ALL patients, the positive expression rate of CDX2 gene in de novo ALL patients was 60.8%, while it obviously decreased in patients with complete remission (CR) (p < 0.05); the expression of CDX2 was increased again in relapsed patients (81.8%). When the expression of CDX2 was analyzed in different risk groups of ALL patients, the CDX2 expression rate in high risk (HR) patients was 91.7%, and that in the standard risk (SR) group was 45.7%. Furthermore, analyses of CDX1 and CDX4 expression in series of ALL samples did not show the expression of these genes. In patients with adult ALL at diagnosis and relapse, the CR rate of patients with CDX2 positive expression was lower than that of patients with CDX2 negative expression (p < 0.05). The median survival time in CDX2 positive expression patients was shorter than that in negative expression patient. It is concluded that expression of CDX2 may correlated with pathogenesis and relapse of adult ALL, but the expression of CDX1 and CDX4 don' t associated with pathogenesis and relapse of adult ALL; the CR rate and prognosis of patients with CDX2 positive expression is lower and poor. The expression of CDX2 may be used as a marker for occurrence, relapse and poor prognosis of adult ALL patients.