Aim To explore the correlation between D-dimer (D-D), procalcitonin (PCT), vitamin D (VitD) and coronary artery disease (CAD). Methods 180 patients with CAD were divided into stable angina pectoris group, unstable angina pectoris group and acute myocardial infarction group according to ACC/AHA diagnostic guidelines. The patients were also divided into single vessel lesion group, double vessel lesion group and three vessel lesion group according to the results of coronary angiography (CAG). 62 patients with normal CAG were used as control group. The differences of general clinical data and serum D-D, PCT, VitD levels were compared between CAD group and control group, and the differences of these three indexes were compared among each group. Results The levels of serum D-D and PCT in CAD group were higher than those in control group, while the serum VitD level was lower than that in control group (P＜0.05). In stable angina pectoris group, unstable angina pectoris group and acute myocardial infarction group, D-D and PCT levels increased in turn, while VitD level decreased in turn (P＜0.05). With the increase of the number of coronary artery lesions, the levels of D-D and PCT increased, and the level of VitD decreased. With the increase of Gensini score, D-D and PCT levels increased, while VitD level decreased. Conclusion The levels of serum D-D and PCT in patients with CAD increase with the severity of lesions, while serum VitD level is opposite.