Objective: To investigate the distribution of marrow cell circle

DNA-aneuploid and their relationship with the types of leukemia and therapeutic effects in childhood acute leukemia (AL). Methods: Mononuclear cellular DNA contents in bone marrow were assessed by flow cytometry (FCM) in 65 patients with childhood AL. Results: The proportion of patients with DNA-aneuploid was different in the various types of AL: DNA-aneuploid in the patients with B-ALL was the highest

in the patients with AML was the second and in the patients with T-ALL was the lowest (Ｐ<0.05).There was no significant difference of the distribution of DNA-aneuploid cell circle between the patients with ALL and the patients with AML (Ｐ>0.05). Sixty-five patients with AL had a higher G0/G1-phase compartment than normal controls. However

the cell circle distribution of the DNA-aneuploid and DNA-diploid without DNA-aneuploid cell in the patients with AL had no significant differences compared with those in the normal controls (Ｐ>0.05). The patients with DNA -diploid cell with DNA-aneuploid had a higher G0/G1-phase compartment than normal controls. It was showed that the patients with high S-phase were more sensitive to chemotherapy than the patients with low S-phase. Conclusion: The analysis of marrow mononuclear cellular DNA content and cell circle distribution by FCM in patients with AL can be helpful in distinguishing the high risk ALL from the standard risk ALL and provide the crucial reference data for the treatment.