Objective: The objective of this study was to determine the clinical use of CGH (comparative genomic hybridization) for detection of fetal aneuploidy from fetal cells (nucleated red blood cells, nRBCs) isolated Methods: Maternal peripheral venous blood sample was collected and treated by heparin. Triple density gradient centrifugation, and MACS (magnetic activated cell sorting) using CD45 and CD 71 were used to isolated the fetal nRBCs. With microdissection, DOP (degenerate oligonucleotide primed)-PCR (polymerase chain reaction), and nick translation, CGH was performed. Results: Fetal nRBCs were successfully isolated from maternal peripheral blood. After microdissection of fetal nRBCs, DOP-PCR. and nick translation, DNA size was suitable for hybridization. In CGH analysis, we can confirm normal female and trisomy 21 male fetus. Conclusion: Prenatal diagnosis from fetal cells in maternal peripheral blood by comparative genomic hybridization shows clinical promise in terms of speed, accuracy, and non-invasiveness. To enable widespread use of this method, further studies involving many cases are warrented.