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目的:分析北京市境外输入新型冠状病毒（SARS-CoV-2）基因组特征及变异情况。方法:2020年2—3月收集北京市来自5个国家的12例输入性新冠肺炎病例呼吸道标本，采用高通量测序法对病毒基因组测序，对序列进行比对和分析，并采用最大似然法构建系统发育树。结果:共获得12条长度为29 826~29 903 bp的SARS-CoV-2基因组序列，与Wuhan-Hu-1参考株的核苷酸和氨基酸序列一致性中位数分别为99.97%（99.94%~99.98%）和99.96%（99.88%~99.98%）。12例基因组共发现22个氨基酸突变位点，其中ORF1ab的P4715L和S蛋白的D614G为最常见突变位点；未发现已报道可明确导致病毒传播力和致病性改变的变异位点，未发现插入和缺失变异。系统发育分析显示，10例欧美国家输入的病毒基因组均位于S-D614G进化支，2例伊朗输入病毒基因组均位于ORF1ab-V378I进化支。结论:未发现北京市2020年2—3月份境外输入的12例病毒基因组携带已报道可明确导致病毒传播力和致病性发生变化的变异位点，仍需持续关注病毒变异情况。“,”Objective:To analyze the genomic characteristics and variations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) imported from abroad in Beijing.Methods:The respiratory tract specimens of 12 imported cases of coronavirus disease 2019 from five countries were collected from February to March 2020 in Beijing. The whole genome sequences of the viruses were sequenced by high-throughput sequencing method. The sequences were aligned and used for further analysis. The phylogenetic tree was constructed by the maximum likelihood method.Results:A total of 12 SARS-CoV-2 genomes with the lengths of 29 826 bp to 29 903 bp were obtained. The medians of identities of nucleotide and amino acid sequences to Wuhan-Hu-1 reference genome were 99.97% (99.94%-99.98%) and 99.96% (99.88%-99.98%), respectively. A total of 22 amino acid mutations were found in the 12 genomes. P4715L in ORF1ab and D614G in S protein were the most frequent mutations. No mutations that have been reported to have clear evidence in causing changes in the transmission ability and pathogenicity of the virus was found. No insertion or deletion was found either. Phylogenetic analysis showed that 10 genomes from European and American countries were clustered into the S-D614G clade while 2 genomes from Iran were in the ORF1ab-V378I clade.Conclusions:No mutation that have been reported to have clear evidence in causing changes in the transmission ability and pathogenicity of the virus was found in the genomes imported from abroad from February to March 2020 in Beijing, and viral variation still needs to be continuously focused.