Aim To investigate the value of serum cardiac myosin binding protein-C (cMyBP-C) in the diagnosis of patients with acute myocardial infarction(AMI). Methods Sixty-two patients with AMI were selected as case group in the department of cardiology from March 2014 to November 2015, and sixty persons of normal physical examination were selected as control group. Enzyme-linked immunosorbent assay (ELISA) method was used for determining the concentrations of serum cMyBP-C. The concentration differences of cMyBP-C, cardiac troponin I(cTnⅠ), creatine kinase(CK-MB) and myoglobin(Myo) between AMI group and control group were compared. Correlations between cMyBP-C and cTnⅠ, CK-MB, Myo were analysed in AMI group. The concentration differences of serum cMyBP-C and cTnⅠ were also compared between the control group and AMI patients with the onset time of less than 4 h. The concentration differences of serum cMyBP-C and cTnⅠ were compared between 12 h after PCI and admission. Results In AMI group, the concentrations of serum cMyBP-C, cTnⅠ, CK-MB and Myo were higher than those of control group(P<0.05). Correlation analysis showed that the level of cMyBP-C had positive correlation with those of cTnⅠ,CK-MB and Myo in AMI group(r=0.876, P<0.05; r=0.632, P<0.05 and r=0.903, P<0.05 respectively). For AMI patients with the onset time of less than 4 h, the level of serum cMyBP-C was higher than that of the control group(P<0.05), but there was not significant difference when comparing the level of serum cTnⅠ and that of the control group(P>0.05). After 12 h of emergency PCI, the level of cMyBP-C was lower than that on admission, but the level of cTnⅠ was higher than that on admission (P<0.05). Conclusions The concentrations of serum cMyBP-C, cTnⅠ, CK-MB and Myo in AMI patients were significantly higher than those of control group on admission and the concentration of serum cMyBP-C had positive correlation with those of cTnⅠ, CK-MB and Myo. cMyBP-C started to rise in 4 h. These suggest that cMyBP-C can be used as early biochemical marker in the diagnosis of AMI. The level of serum cMyBP-C decreased obviously after 12 h undergoing emergency PCI in AMI patients. This suggests that cMyBP-C can be used as an early indicator for evaluating the effect of PCI.