Regulation of gene expression is one of the most important responses of cells to DNA damage induced by radiation. A novel expressed sequence tag (EST) fragment had been cloned from human embryo lung cells induced by 50cGy radiation and named RIG1. To clone the full-length cDNA of RIG1, a non-cloned cDNA library of human embryo lung cells induced by low dose irradiation had been established. This library was used as template in enchanced nest RACE PCR and biotin-labeled probe was used for further purification. The 3′ flanking sequence of this EST was cloned and sequenced with this set of technology. It was illuminated by homology analysis that this 3′ flanking sequence and the original EST are well aligned with a BAC clone of 20^th chromosome and the predicted exons' sequence of this chromosome is well consistence with the real EST. Thus the RIG1 can be roughly located in 20^th chromosome. By use of the exons' sequence predicted from chromosome sequence by GENSCAN, full-length of RIG1 gene has been cloned. Chromosome location of RIG1 gene is further determined by this successful verification of Bioinformatics prediction by experiment. By the same step, genome sequence of RIG1 has been determined. Therefore,by the combined use of Bioinformatics analysis，the full-length cDNA sequence and genome sequence of RIG1 gene are obtained and the predicted protein sequence is determined.