///In this paper, historical felt earthquakes in Hunan Province and its 7°×7° neighborhood are analyzed. The authors form conjectures upon G-R relationship that the catalogue constituted by earthquakes of a magnitude more than M3 1/2 is complete grossly from 1509 in research region where modern seismicity is weaker, the intervals between any two stronger earthquakes are relatively longer, and earthquake frequency is lower. It is difficult to connect historical stronger earthquake with modern earthquakes in seismicity research. With historical felt earthquakes taken in account in our work, statistical samples with seismicity parameters increase significantly. Correlation coefficient of b-value fitting is raised, and variance is decreased.