In recent years, with deeper investigation on black earths found by archeologists in Amazon region, Brazil, it is considered that amendment of biochar pyrolyzed from biomass under little oxygen can not only alleviate global warming speed as a result of storing carbon in soil, but also may improve soil quality which would secure food safety. In this paper, biochars’ properties, influences on crop yield and nutrients uptake, decomposition and effects on soil carbon turnover, and degradation and bioavailability of organic pollutants were compiled. Furthermore the key perspectives were highlighted for future research.