To analyze the basic character of a novel Homosapiens synapse associated protein gene(FRG4) with bioinformatics.FRG4 full-length sequence was obtained by hot-start PCR from human fetal liver library and its genomic constitution,the multi-sequences homology,the transmembrane domains,hydrophilicity and hydrophobicity,as well as its functional and structural domains were analyzed and predicted by bioinformatics.We have successfully attained the fulllength cDNA sequence of FRG4,bioinformatic analysis shows FRG4 gene has 99%homology with Homosapiens synapse associated protein 1(SYAP1),consists of 9 exons and 8 introns and located in Xp22.2.None transmembrane domains but a BSD domain was discovered,and its encoding protein is probably a water-solubility protein.