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目的:揭示甘肃省境外输入新型冠状病毒肺炎(Coronavirus Disease 2019, COVID-19)病例新型冠状病毒(2019 novel coronavirus, 2019-nCoV)基因组特征及变异情况，为全省COVID-19疫情防控工作提供科学参考。方法:收集2020年甘肃省来自7个国家的输入COVID-19病例呼吸道标本，采用二代测序技术进行基因组测序，获得的全基因组序列进行比对和分析，使用MEGA软件基于邻接法构建系统进化树。结果:共获得46条长度为29 605~29 903 bp的2019-nCoV基因组序列，与武汉参考株(GenBank序列号：NC_045512.2)对比分析发现，甘肃省入境病例的2019-nCoV全基因组序列核苷酸突变位点数的中位数(最小值~最大值)为10(7~24)个。甘肃省7个入境国家的所有2019-nCoV全基因组序列中，共发现134个核苷酸突变位点，分布于11个开放阅读框(open reading frame, ORF)。不同蛋白中核苷酸变异前3：ORF1ab(78)、S(20)、N(12)，134个核苷酸突变中，有82个导致氨基酸突变，且均为错义突变，未见插入或缺失突变类型；不同蛋白中氨基酸变异前3：ORF1ab(46)、S(11)、N(10)；S蛋白的受体结合域(receptor binding domain, RBD)关键位点均未发生变异。结论:甘肃省境外输入病例中尚未发现2019-nCoV传播力和致病性相关变异位点。“,”Objective:To disclose the genome characteristics and mutations of 2019 novel coronavirus (2019-nCoV) strains from the imported cases of Coronavirus Disease 2019 (COVID-19) in Gansu province, n thereby to provide scientific reference for the prevention and control of COVID-19 in Gansu province.n Methods:The respiratory tract specimens of imported COVID-19 cases from seven countries in Gansu province in 2020 were collected. The virus genome was sequenced by the second-generation sequencing technology, the whole genome sequences were compared and analyzed, and the MEGA software was used to construct a phylogenetic tree based on the neighbor-joining method.Results:A total of 46 2019-nCoV genome sequences with a length of 29 605~29 903 bp were obtained. Compared with the Wuhan reference strain (GenBank ID: NC_045512.2), it was found that the median (minimum to maximum) number of the nucleotide mutations of the 2019-nCoV genome sequence of the imported cases was 10 (7-24). A total of 134 nucleotide mutation sites were found in all 2019-nCoV genome sequences from 7 entry countries in Gansu province, distributed in 11 open reading frames (ORFs). The top three nucleotide mutations in different proteins: ORF1ab (78), S(20), N(12). Among the 134 nucleotide mutations, 82 caused amino acid mutations, and all of them were missense mutations. No insertions or deletions were seen. Types of deletion mutations, the top three amino acid mutations in different proteins: ORF1ab (46), S(11), N(10); the key sites of the receptor binding domain (RBD) of the S protein have not been mutated.Conclusions:No imported cases in Gansu province have been found to carry the reported mutations that can clearly lead to changes in the spread and pathogenicity of 2019-nCoV.