UVC irradiation rapidly and strongly induces protein expression of the early growth response‐1 gene (Egr‐1) encoding a transcription factor which may have a protective function against UV damage. In this paper, we further investigate mechanisms responsible for such induction. We show that UVC irradiation also induced Egr‐1 mRNA expression, increased transcription rate by nuclear run‐on assay and stimulated Egr‐1 promoter activity by CAT assay. The Egr‐1 mRNA stability remained unchanged in UVC‐treated cells. On the other hand, UVC irradiation slightly extended Egr‐1 protein half‐life. The induction of Egr‐1 by UVC was observed in many different cell types. UVA and UVB also strongly induced Egr‐1 expression. These results indicate that UVC regulates Egr‐1 expression at transcription level. The induction pattern of Egr‐1 by UV suggests the importance of Egr‐1 in the UV response. J. Cell. Biochem. 73:227–236, 1999. © 1999 Wiley‐Liss, Inc.