In this paper, the MODIS (Moderate Resolution Imaging Spectroradiometer) data carried on Aqua and Terra satellites, GOES (Geostationary Operational Environmental Satellite) infrared satellite cloud imagery provided by NASA (National Aeronautics and Space Administration) and ERA5 (the fifth generation) global reanalysis data issued by ECMWF (European Centre for Medium-Range Weather Forecasts) with hourly time interval and horizontal resolution of 0.25°×0.25° are used to analyze the characteristics and geographical distribution of a total of 439 “Actinoform Clouds” over the Pacific Ocean from 2012 to 2016. The results show that most of the “Actinoform Clouds” exhibit nearly circular or elliptical shapes, with an obvious center of cloud system and clear radical arms extending from the center to outside, which look like a wheel in ancient times. The statistical analysis indicates that about 85% of the “Actinoform Clouds” occur over the Southern Hemisphere, and most of them occur over the Southeast Pacific Ocean off the coast of Peru. “Actinoform Clouds” occur throughout the whole year. High frequency of such clouds is observed in June, July and August, medium frequency in May, September and October, and low frequency in January, February, March, April, November and December, respectively. The atmospheric inversion layer has important impact on the formation and dissipation of the “Actinoform Clouds”, and the interior of the cloud system is dominated by upward motion; some of the “Actinoform Clouds” exhibit rotation patterns; the upward and downward motions affect the structure of the cloud system.