Abstract: Objective To investigate the value of 64-MSCT combined with Ig E and Hcy for estimating the stability of coronary artery plaques of patients with coronary heart disease. Methods The 83 patients in-hospital doubtful or diagnosed coronary heart disease admitted to our hospital were enrolled. All patients conducted with CT tomography and coronary angiography(CAG),the result of CT tomography of who were negative,were divided into control group. According to the results of CAG and medical history,the others were divided into acute coronary syndrome(ACS) group,stable angina pectoris(SAP) group. According to the results of coronary artery plaques detected by MSCT,both ACS and SAP groups were further divided into vulnerable plaque group,mixed plaque group and stable plaque group. The levels of serum immunoglobulin E(Ig E) and homocysteine(Hcy) were detected. The clinical characteristics of patients were recorded. Ig E and(Hcy) were measured. Results 1The distribution of vulnerable plaques in ACS group was higher than that in SAP group(P < 0. 05),while that of stable plaques lower than in SAP group(P < 0. 05). 2The levels of homocysteine(Hcy)in SAP and ACS group were higher than those in control group(P < 0. 05),and there was significant difference between SAP and ACS groups(P < 0. 05). The levels of Ig E were not significant different between SAP and ACS groups(P >0. 05),3The levels of homocysteine(Hcy) in every plaque group were all obviously higher than those in the control group(P < 0. 05),and those in vulnerable and mixed plaque group were also higher than those in stable plaque group(P < 0. 05). The levels of homocysteine(Hcy) in vulnerable plaque group were higher than those in mixed plaque group(P < 0. 05). The levels of Ig E in every plaque group were not higher than those in the control group(P > 0. 05). Conclusion 164-MSCTcan accurately characterize the composition of the coronary artery plaques. 2The relationship between the levels of Hcy and the stability of coronary artery plaques were intimate,which can reflect the stability of coronary artery plaques,the relationship between Ig E and unstable coronary artery plaques is not notable. 3The detection of 64-MSCT combined with homocysteine(Hcy) had predictive value of unstable coronary artery plaques.