The validation of many synthetic chemicals that may pose a genetic hazard in our environment is of great concern at present. Since these substances are not limited to the original products, and enter the environment, they have become widespread environmental pollutants, thus leading to a variety of chemicals that possibly threaten the public health. In this respect, the regulation and evaluation of the chemical hazard play a very importaut role to eovironment and human health. The c1astogenicity of 17 synthetic chemicals was evaluated in Chinese hamster lung fibroblast cells in vitro. 2-Nitroaniline (CAS No. 88-74-4) induced chromosomal aberrations with statistical significance at the concentration of 86.3μg/ml in the absence of metabolic activation system. 1-Chloroanthraquinone (CAS No. 82-44-0) which is one of the most cytotoxic chemical among 17 chemicals tested revealed no c1astogenicity in the range of 0.8~3.0μg/ml both in the presence and absence of S-9 metabolic activation system. From the results of chromosomal aberration assay with 17 synthetic chemicals in Chinese hamster lung cells in vitro, 2-Nitroaniline (CAS No. 88-74-4) revealed weak positive c1astogenic results in this study.