Objective:To analyze the structure characteristics of the breast cancer susceptibility protein 1(BRCA1) gene sequence by bioinformatics methods and predict the relationship between mutations of functional coding regions in BRCA1 and the pathogenic genetic effects. Methods:The molecular phylogeny,conservation,selection pressure,domains,three-dimensional structure and missense of BRCA1 were analyzed by online Bioinformatics analysis tools such as Maximum Likelihood,ClustalW,SMART,SELECTON and so on. Results:Total 195 fixed-residue sites(10.5%)and 393 conservative sites(21.1%),of which distribution is non-randomness,were obtained. A big difference in the BRCT domain was founded between human and other species,which indicated the role of BRCT domain in BRCA1 gene of various species is difference. The high pathogenic mutation rate in conservative sites was confirmed by correlation analysis. Conclusion:Taking full advantage of relevant resources,the BRCA1 sequence structure analysis based on bioinformatics methods can deepen our understanding of the correlation of BRCA1 gene mutation and tumor.