Objective To analyse the correlation between the characteristics of coronary plaque in coronary heart disease (CHD) patients with phlegm-blood stasis syndrome (PBS) and blood stasis syndrome (BSS). Methods Patients were divided into different groups based on Chinese medicine (CM) syndrome differentiation. The baseline demographics and clinical variables were collected from the medical records. Additionally, the characteristics of plaque and pathological manifestations in coronary artery were evaluated using intravascular ultrasound (IVUS). Results A total of 213 CHD patients were enrolled in two groups: 184 were diagnosed with PBS and the remaining 29 were diagnosed with BSS. There were no significant differences in age, body mass index, proportions of patients with high blood pressure, diabetes mellitus, smoking, hyperlipidemia, history of coronary artery bypass graft and percutaneous coronary intervention, medications, index from cardiac ultrasound image, blood lipids and C-reactive protein between the two groups (P>0.05), except gender, weight and proportions of IVUS observed target vessels (PP<0.01). More adverse events such as acute myocardial infarction (P=0.003) and unstable angina (P=0.048) were observed in BSS. Additionally, dissection, thrombus and coronary artery ectasia were significantly increased in BSS (PP<0.01). In contrast, PBS had more patients with stable angina and chronic total occlusion with significantly higher SYNTAX (synergy between percutaneous coronary intervention with Taxus and coronary artery bypass surgery) scores (PP<0.01). Moreover, dense-calcium was significantly elevated in PBS (P<0.01). Conclusions Coronary plaque characteristics were correlated with different CM syndromes. Patients with PBS were associated with a higher degree of calcified plaque and severe coronary artery stenosis, indicating poor clinical prognosis but with a low probability of acute coronary events. In contrast, the degree of calcified plaque in patients with BSS remained relatively low, and plaque was more vulnerable, resulting in the possibility of the occurrence of acute coronary events remaining high.