Viruses have been recognized as the most abundant biological entities on Earth. Studies of marine viruses have shown that viruses are of very high abundance and genetic diversity, and viruses make great contribution to the mortality of prokaryotic and eukaryotic microbes. There have been both empirical data and conceptual models for understanding the impact of viruses on biogeochemical processes in the sea; the responses of marine viruses to global changes have also received much attention. Soil viruses, however, have been studied very poorly. We have yet little information about the abundance, distribution, and environmental response of soil viruses. It is known that soils contain a great amount of organic matters, and may function as an important carbon source. Soil viruses may regulate the abundance and activity of soil microbes, with profound consequence for global carbon cycles. It is thus crucial to integrate viruses into ecosystem ecology, either in the sea or on the land.