In this study, factor analysis and mass regression were used to identify four fine particulate matter sources and estimate their contributions to the ambient air pollution in Beijing. The identified sources were traffic re-suspended soil, mixed industrial, oil combustion, and secondary sulfate. The estimated source contributions were then introduced into two models as exposure variables to explore the relationships between cardiovascular responses in mice and PM exposures. We observed that PM2.5 has a small negative acute effect on heart rate, but the individual source factors showed much more significant effects. Traffic re-suspended soil had the most significant effect on heart rate, with a positive contribution on the day of exposure, and negative on day lag 1. Acute heart rate variability outcomes were better explained by total PM2.5 than by the source components. Chronic effects were observed as decreased heart rate, but increased heart rate variability outcomes.