A study of the coefficient of sensitiveness between permeability and effective pressure of coal samples is conducted based on experimentation and analysis. Test results indicate that the permeability of coal samples drops rapidly as the effective pressure increases under a low effective pressure level. The variation relationship between them can be described by an exponential equation. The coupling mechanism of seepage in coal beds has not been completely made clear so far, and the coupling factors affecting the permeability of coal samples are too complex to describe. The coefficient of sensitiveness between the permeability of coal samples and effective pressure is defined accordingly so as to normalize these factors. It is shown that the variation relationship between the coefficient and the effective pressure can be described by a power function. Such a coefficient can evaluate well the changing trend of the permeability of coal samples related to the effective pressure. The between coal sample permeability and the effective pressure is deduced based on the coefficient of sensitiveness.