In order to make a prediction of earthquakes, we have to find out any relationship between electromagnetic phenomena and earthquakes.
We have been observed VHF radio waves that propagate from line-of-sight region for several years. During the observation, we noticed some anomalous propagation associated with lightning storms on the VHF band. When strong lightning storms occur, the anomalous propagation sometimes appears on the VHF radio waves. To get more absolute relationship between anomalous propagation and earthquakes, the anomaly associated without earthquakes should be excluded from anomaly data. Therefore, we investigate the relationship between the anomalous propagation on VHF radio waves and occurrences of lightning storms by statistical original method. In this paper, using statistical estimation, we find out strong relationship between the anomalous propagation on the VHF band and occurrences of lightning storms near the wave propagation path.