The objectives of this study are to seek answers to the following issues: Why are different ways used to analyze coal's reactivity? Could different methods of measuring coal's reactivity be comparable? Is there any relation among them? Two methods, coal hydrogenation and coal pyrolysis, were employed to investigate coal's reactivity. Six kinds of coals from lignite to anthracite were studied. It was found that the activity energy calculated from the thermogravimetry analysis of coal pyrolysis had a limitation; the initial and maximum temperature of weight loss during coal pyrolysis was more relevant to coal reactivity. These two temperatures, and the amount of hydrogen transferred during coal that reacted with the H-donor THN, were comparable. In the mean time, the methodological canonical relation analysis was used theoretically to compare the two kinds of reactivity and has a proof from a mathematic point of view. Results showed that these two kinds of reactivity had similitude.