Abstract: Objective To study the detection on DNA damage by single cell gel clectrophoresis assay technology during rats.neural tube defect process.Methods Twenty pregnant rats were randomly divided into control group and NTDs model group according to their weight.On the 13 d of gestation,the pregnant rats of the model group were given cyclophsphamide 12.5 mg/(kg·bw)via intraperitoneal administration,the control group was given 0.3 ml N.S in the same way.On the 14 d of gestation,two rats of each group were executed.The DNA damage of three embryo's brain tissue in each pregnant rat was checked through single-cell gel electrophoresis technology.Furthermore,influence factors of SCGE were analyzed.Results Comet cells were found in the model group but were not found in control group.The comet cells showed small head and big tail.Tail length of comet cells in model group(16.35?5.59)Lmwas longer significantly than that of neuron cells in control group(7.28+1.76)Lm.Ratio of abnormity in model group(67%)was significantly increased(P<0.05)and the developmental index was significantly decreased in model group(P<0.05).T here were some factors affecting the experiment including concentration of cell suspension and gel,time of split as well as fluo rescent staining.Conclusion DNA damage in NTDs can be checked by single cell gel electro phoresis assay technology.Besides,some details should be emphasize in order to improve the sensitivity and specificity.