Recent studies have showed that by artificial biochar addition is one reliable way to reduce atmospheric carbon dioxide concentrations. Biochar has slowly decomposition rate for the special construction and can be sequestrated in soil for a long time, which is important for stabilizing soil organic carbon storage, increasing soil carbon storage capacity, retaining soil fertility, and improving soil texture. Biochar added in soil can chang soil aggregate structure, moisture permeability, nutrient absorption and microbial activity, causing a priming effect to transform soil organic carbon turnover. However, the reports about the priming effect of biochar addition are inconsistant. The effect may be positive, negative or not at all. The extent, direction and persistence of priming effect caused by interaction between biochar and soil remain uncertain. This paper reviewed the most recent literatures regarding the effects of biochar applications on soil environment including soil carbon sequestration and emission, soil physical and chemical properties, microbial activity and the structure dynamic changes of biochar itself, and analyzed the extent, direction and persistence of the priming effect of soil carbon by biochar addition.The positive priming effect on native soil organic carbon mineralization could be resulted from co-metabolic effect between labile components of biochar and microbial activities with improving soil organic carbon mineralization. The negative priming effect on native soil organic carbon mineralization may be caused by increasing stability of native soil organic carbon or inhibitory native soil microbial activity. Finally, the paper summarized the existing problem including addition dosage, the interaction among biochar, soil community and plant, risk prediction and assessment by biochar addition and the necessity of longer study, which will lay the scientific basis for long-term ecosystem C sequestration and provide choose, reference for climate change.