The relationship between H3+ emissions in the Jovian sub-auroral region and auroral activity inside the auroral oval was examined using 3.53-¿m image data from the IRTF Galileo support monitoring program of NASA. The sub-auroral emission region of H3+ was defined as a diffusive and weak emission region surrounding the auroral oval with a gradual decrease in intensity at lower latitudes beyond 6 RJ. The size of this region was found to vary approximately in proportion to the Jovian auroral activity. We discuss some possible sub-auroral emission mechanisms and suggest that the emission would be caused by precipitation from the inner magnetosphere associated with the higher latitude auroral activity, implying that the Jovian magnetospheric activity is tightly connected between the inner and middle magnetosphere.