【目的】 旨在解析广西壮族自治区的松墨天牛Monochamus alternatus遗传多样性和遗传结构特征，深化对松墨天牛种群分化和生态适应规律的理解。【方法】 基于线粒体细胞色素c氧化酶亚基Ⅰ（Cytochrome coxidase subunitⅠ, COⅠ）序列，对广西11个松墨天牛群体的遗传多样性、遗传分化和遗传结构进行比较分析。利用Bioedit和DnaSP 5.0软件分析遗传多样性，使用Arlequin 3.5软件进行中性检验与遗传分化分析，采用Ppoart 11软件绘制单倍型网络图，并结合国内外其他样本使用MEGA 6绘制系统进化树。【结果】 分析了167头松墨天牛635 bp的COⅠ序列，检测到29个变异位点，占所有位点的4.57%。整体单倍型多样性为0.858，核苷酸多样性为0.004 52。 11个地理种群间的遗传距离为0.001-0.010，Mentel检验结果表明，遗传距离和地理距离没有显著相关性（P > 0.05）。AMOVA分析显示，种群内遗传变异高于种群间（60.09% > 39.91%），固定系数Fst值为﹣0.047-0.889，各种群间存在不同程度的遗传分化。单倍型网络图将32个单倍型分为3个进化中心，其中Hap8为原始单倍型，共享单倍型占所有单倍型的34.38%。【结论】 广西松墨天牛具有较高的遗传多样性，遗传变异潜力和环境适应能力较强。人为活动、环境特点和社会特点等因素影响着广西松墨天牛的种群遗传结构，使其能够存在远距离的基因交流。

 [Aim]  Analyzing the genetic diversity and genetic structure characteristics of the pine sawyer beetle Monochamus alternatus in the Guangxi Zhuang Autonomous Region, to deepen the understanding of population differentiation and ecological adaptation patterns of the M. alternatus. [Methods]  Variation in the sequence of the mitochondrial cytochrome coxidase subunit Ⅰ (COⅠ) gene between specimens from 11 geographical populations in Guangxi was measured and compared. Bioedit and DnaSP 5.0 software were used to analyze the genetic diversity of M. alternatus, and Arlequin 3.5 software to perform a neutrality test and analyze genetic differentiation. Popart 11 software was used to draw a haplotype network diagram, and MEGA 6 to draw a phylogenetic tree including other domestic and foreign specimens. [Results]  In the analysis of 635 bp COⅠ sequences from 167 individuals of M. alternatus, 29 variable sites were detected, accounting for 4.57% of all sites. The overall haplotype diversity was 0.858, and nucleotide diversity was 0.004 52. The genetic distances among the 11 geographic populations ranged from 0.001 to 0.010, and the Mantel test results indicated no significant correlation between genetic distance and geographic distance (P > 0.05). AMOVA analysis showed that within-population genetic variation was higher than between-population variation (60.09% > 39.91%), with Fst values ranging from -0.047 to 0.889, indicating varying degrees of genetic differentiation among different populations. The haplotype network diagram divided 32 haplotypes into 3 evolutionary centers, with Hap8 being the ancestral haplotype, and shared haplotypes accounting for 34.38% of all haplotypes. [Conclusion]  The M. alternatus in Guangxi exhibits high genetic diversity, strong potential for genetic variation, and environmental adaptability. Factors such as human activities, environmental characteristics, and social features influence the genetic structure of M. alternatus populations in Guangxi, enabling gene flow over long distances.