Aim To investigate the association between serum remnant cholesterol (RC) level and coronary heart disease (CHD) and myocardial infarction (MI). Methods Two-sample Mendelian randomization (MR) analysis was used to investigate the potential causal association between RC and CHD, MI. The inverse variance weighted (IVW) model was used as the main analytical method for the two-sample MR analysis and was followed by sensitivity analysis, including heterogeneity test, horizontal pleiotropy test, and leave-one-out analysis,to evaluate the robustness of the MR results. Results The IVW method showed statistically significant associations between RC and increased risk of CHD and MI (CHD:OR=1.7,5%CI:1.40～1.76, P＝2.01 E－14; MI:OR=1.9,5%CI:1.40～1.79,P＝1.26E－13). MR-Egger regression results suggested that the screened single nucleotide polymorphisms (SNP) were not genetically pleiotropic with CHD and MI (The P values for CHD and MI were P＝0.924 1 and P＝0.740 5, respectively).Conclusion Elevated serum remnant cholesterol level is causally associated with an increased risk of CHD and MI.