We study the effect of geomagnetic storms on the sub-ionospheric VLF/LF propagations based on 2-year data from the network observations in Japan. Three statistical parameters such as average signal amplitude, variability of the signal amplitude, and nighttime fluctuation were calculated. These statistical parameters indicate significant anomalies during the geomagnetic storm in the high-latitude paths. While mid-latitude and low-mid latitude paths have smaller influence from the storm activity.