This study was purposed to investigate the difference of zo-1 gene promoter methylation between healthy individuals and acute leukemia patients. BS-PCR method was used to detect the status of zo-1 gene methylation in healthy individuals, acute leukemia patients and leukemic cell line NB4 cells. The results showed that zo-1 gene was hypomethylated in bone marrow samples from healthy individuals (1.9%). In newly diagnosed AL and relapsed patients, the rate of zo-1 gene methylation was 93.2% and 66.9% respectively, while it was 16.4% in AL patients in complete remission, which was much higher than that in healthy individuals. There was significant difference between them. It is concluded that as compared with healthy individuals, zo-1 gene in acute leukemia patients is hypermethylated and with different degrees in various phases of leukemia. Analysis of zo-1 gene methylation status may be useful to monitor the development of acute leukemia.