Abstract: Biochar is a relatively stable carboncious material converted from organic waste.Currently more and more attention and efforts are being given worldwide to development of technologies of converting agricultural waste into biochar and field experiments are being carried out on effect of its use on expansion of carbon pool in and mitigation of carbon emission from farm fields.A brief introduction is presented to the background of the development of biochar technologies as well as the progresses worldwide in the study on production and application of biochar.Meanwhile discussions are carried out on potential effects of the application of biochar on crop productivity and sequestration/release of carbon in agriculture and hence on climate change,and analyses are done on the possibility of including the use of biochar into the world C trade and the country’s independent C emissions trading market.Eventually suggestions are brought forth for research on production and application of biochar in agriculture of the country.