Abstract: The dose-effects,time-effects on toad(Bufo bufo gargarizans)nuclei aberration test with a single intraperitioneal injection of Cyclophsphamide ( CP)and Formaldehyde ( FD ) were investigated. The experimental results showed that toad nuclei aberration rate existed a significant linear dose-response relationship in certain region. The results of data on time-effect showed that the nuclei aberration rate reached maximum 12 hr. after the toxic chemicals were injected.In addition,by comparison of nuclei aberration rate with micronuclei, frequency the author suggested that the nuclei aberration [test was more sentitive and more reliable screening system than micronuclei test in monitoring environmental mutagenes and ecotoxicity.Nuclei aberration test will probably become a new to-xicity index in the toxicity test of environmental pollutants, and a new research method for amphibian ecotoxicology.