Quantification of myeloid cell-DNA in 30 cases with aplastic anemia (AA) was performed with computer image analysis techniquee pre- and post-treatmentally with Bushen Huayu recipe respectively, and compared with that of a control group of 30 healthy subjects. The results showed the average level of DNA in myeloid cells from AA patients was significantly lower than that of control (P < 0.01) prior to the treatment and it raised to the same level approximately as that of control after the treatment. This change of DNA quantity might result from the improvement of microcirculation or(and) stimulus to hematopoietical cells which accelerated the DNA anabolism in these cells.