ObjectiveTo explore the characteristics of the tongue coating microbiota in patients of coronary heart disease （CHD） with qi deficiency and blood stasis syndrome. MethodsA total of 27 CHD patients with qi deficiency and blood stasis syndrome， 29 patients with non-qi deficiency and blood stasis syndrome， and 20 healthy individuals were included in this study. The tongue coating microbiota of the participants was analyzed using 16S rDNA high-throughput sequencing technology， followed by Alpha and Beta diversity analyses and comparisons of microbial abundance. ResultsA total of 479 operational taxonomic units （OTUs） were detected， among which 245 OTUs were shared across all three groups. There were 33 OTUs unique to the qi deficiency and blood stasis syndrome group， 21 OTUs unique to the non-qi deficiency and blood stasis syndrome group， and 121 OTUs unique to the healthy group. The observed species count （Sob）， total species richness （Chao1）， abundance-based coverage estimator （ACE）， and Shannon diversity index were significantly lower in the qi deficiency and blood stasis syndrome and non-qi deficiency and blood stasis syndrome groups compared to the healthy group （P＜0.05）. Principal coordinate analysis （PCoA） of the tongue coating microbiota showed significant differences in distance matrices among the three groups （P＜0.05）. Compared with the healthy group， the qi deficiency and blood stasis syndrome group exhibited an increased abundance of Actinobacteria， Patescibacteria， Spirochaetes， Verrucomicrobia， Rothia， TM7X， Gemella， and Corynebacterium， while Fusobacteria， Cyanobacteria， Leptotrichia， and Lactobacillus decreased （P＜0.05）. In the non-qi deficiency and blood stasis syndrome group， Actinobacteria， Verrucomicrobia， Rothia， and Corynebacterium increased， whereas Cyanobacteria and Lactobacillus reduced （P＜0.05）. When comparing with the non-qi deficiency and blood stasis syndrome group， the qi deficiency and blood stasis syndrome group had a significantly higher abundance of Patescibacteria， Peptostreptococcus， Solobacterium， Filifactor， Moraxella， Porphyromonas endodontalis， and Capnocytophaga， while Cyanobacteria reduced （P＜0.05）. Conclusuion Patients with CHD of qi deficiency and blood stasis syndrome exhibit a decrease in beneficial bacteria and an increase in pathogenic bacteria. Patescibacteria， Peptostreptococcus， Solobacterium， Filifactor， Moraxella， Porphyromonas endodontalis， and Capnocytophaga were identified as the key differential microbiota distinguishing qi deficiency and blood stasis syndrome from non-qi deficiency and blood stasis syndrome patients.