The BNLF-1 gene located in U₅-TR region of Epstein-Barr virus genome encodes a latent membrane protein (LMP-1). As the protein can transform B cells and plays a key role in the carcinogenesis of EB virus, so it has become the “hot spot” of studying for the diseases relavance to EB virus, such as nasopharyngeal carcinoma, Burkitt's lymphoma, Hodgkins disease etc, and also the molecular biology of EB virus. A series of achievements have been achieved, the progress in following aspects are reviewed: 1. the structure and expressing regulation of BNLF-1 gene; 2. the structure and biochemical function of LMP-1 protein; 3. the biological function of LMP-1; 4. looking forward to the future.