Glycidyl methacrylate(GMA) can induce the phenotype transformation of human embryonic lung fibroblasts. The transformed cells prolifeated rapidly with a higher in the ratio of nucleus to cytoplasm, and their life span extended notably. The transformed colonies exhibited in extensive random orientation and the cells crossing-over. The transformed cells could be agglutinated by lower concentration of ConA and could grow in semisolid agar. The chromosome abberations could occur in transformed fibroblasts. These results suggest that GMA is able to induce malignant transformation of mammal cells, and it may be carcinogenic to human.