Abstract: In order to study the pathway and mechanism of biochar affecting soil N₂O and CH₄ emissions, based on comprehensive evaluation of published researches, the factors, pathway and mechanism that biochar affected soil N₂O and CH₄ emissions were analyzed, the principles of biochar addition in different types of soil were then proposed. The key problems that should be paid attention to in future studies were pointed out: (1) the characters of these two GHG emissions in soil should be explicited, the biochar type should be chosen according to the local soil conditions. (2) The time and amount of biochar addition should be reasonable. (3) Nowadays because of the differences of biochars and soil types that different scholars used, the research conclusions about the effects of biochar on the soil N₂O and CH₄ emissions were still controversial. In future, the more clear conclusions about the effects of biochar on the soil N₂O and CH₄ would be attained till the experiments of returning biochar into field according to the local soil type should be continued after the complement of biochar applying standard.