In this study, remotely sensed infrared brightness temperature data from the China Geostationary Meteorological Satellite FY-2C/E from 2006 to 2013 are full time-space analyzed to determine the dominant frequency and amplitude using the relative power spectrum method. The variation in time and space in the relative power spectrum of each frequency was analyzed and compared with the three elements of 17 earthquakes having magnitudes greater than 5.0 in Zhejiang Province and its neighboring area. The following results were obtained: the relative power spectrum anomaly of infrared brightness temperature appears before nine earthquakes. The corresponding ratio of the first three dominant frequencies is higher than that of last three ratios. The anomalies occurred several days or months before earthquakes, and most earthquakes occurred after the anomalies reached the maximum value or were recovering. A few earthquakes occurred before the anomalies reached the maximum value. The anomalies increase in strength and then disappear, in a process from sporadic to conglomerate or banded along the fault zone. Anomaly time and amplitude and the time period from the appearance of the anomaly until the earthquakes occurred have no obvious relation with the three elements of the earthquake.