Detailed observations of Jovian decimetric radiation (DIM) from relativistic electrons in the inner Jovian radiation belt was carried out to seek the existence of a short-term variation which has information on the electromagnetic disturbances in the inner Jovian magnetosphere. Results demonstrated the DIM flux enhancement continuing for a few days for the case of November 1996. It was shown that the relativistic electrons were highly anisotropic during the DIM flux enhancement. The correlation between the DIM flux enhancement and the solar F10.7 flux enhancement was also detected. A model simulation suggested that the observed DIM flux variation was caused by the enhanced radial diffusion due to the intense solar UV/EUV event which heated the Jupiter's upper atmosphere. ¿ 1999 American Geophysical Union