Objective To study the value of left atrium(LA) volume and function in patients with different degrees of coronary artery disease by using 3D speckle tracking imaging (3D-STI). Methods According to the results of coronary angiography, 81 patients with confirmed coronary heart disease (CHD) were divided into mild lesion group (Gensini score<25,n=31),moderate lesion group (25≤Gensini score＜50,n=26),severe lesion group (Gensini score≥50,n=24),and 31 healthy subjects at the same period were selected as control group.LA volume indexs including LA maximum indexs volume (LAVImax), LA minimum indexs volume (LAVImin), LA presystolic indexs volume (LAVIpre) and three-dimensional strain parameters of LA including global longitudinal strain (GLS), global radial strain (GRS) and global circumcircular strain (GCS) were obtained by 3D-STI technique.LA ejection fraction, passive and active ejection fractions (LAEF, LApEF, LAaEF) were calculated. Analysis and comparison between row groups and the correlation between Gensini score and LA volume and strain parameters were analyzed. Results ① Compared with the control group, GLS and GCS were decreased in the mild lesion group (all P <0.05); Compared with the control group and the mild lesion group, the LAVImin and LAVIp increased, while LAEF, LApEF, GLS and GCS decreased in the moderate lesion group (all P <0.05); Compared with the other three groups, the LAVImin, LAVIp and LAVImax in the severe lesion group were increased, while LAEF, LApEF, LAaEF, GLS, GCS and GRS were decreased (all P <0.05). ② LAVImin and LAVIpre were positively correlated with Gensini score (r=0.769,r=0.550,all P<0.05);GCS, GLS, GRS showed negative correlation with Gensini scores (r=-0.618, r =-0.577, r=-0.549, all P < 0.05). Conclusions 3D-STI can effectively evaluate the LA volume and function of CHD patients with varying degrees of coronary artery lesions, providing evidence for early intervention and treatment of CHD patients.