Abstract: With the development of agricultural modernization，more and more people are paying attention to the environmental problems caused by agricultural carbon emissions．According to the statistical and survey data from 1993 to 2011 from China Rural Statistical Yearbook and Gansu Rural Yearbook，based on six kinds of factors （carbon sources，chemical fertilizers，pesticide，farming films，agricultural diesels，irrigation and tillage in agricultural produ- ction），this paper calculates the amount of agricultural carbon emissions and analyzes the quantitative and the structure characteristics of the carbon emission in Gansu Province during the period from 1993 to 2011. The results show as follows：the amount of agricultural carbon emissions is in the gradual upward trend in 19 years，which increased from 66.37 ten thousand tons in 1993 to 207.92 ten thousand tons in 2011，the average annual growth rate is 6.67%；The agricultural carbon emission intensity is also increased year by year，which increased from 182.40 kg·hm-2 in 1993 to 510.93 kg·hm-2 in 2011，the average annual growth rate is 6.01%；In terms of the structure of agricultural carbon emissions，fertilizers are the largest carbon source，the average ratio reaches 49.40%，the next is agricultural films，the average ratio reaches 30%. Further more，the paper decomposes the influencing factors of agricultural carbon emissions by using LMDI model. It is shown that agricultural economic development makes the key impact on carbon emissions. overall，agricultural economic development and agricultural labor scale play an active role in agricultural carbon emissions，compared with the carbon emission load in 1993，from 1994 to 2011 agricultural economic development increased 255.65 ten thousand tons of carbon emissions as well as agricultural labor scale increased 2.45 ten thousand tons of carbon emissions. While the production efficiency and structure restrain carbon emission，which cut 114.70 ten thousand tons and 2.36 ten thousand tons of carbon emissions，respectively. Finally，according to the conclusion of this study，some advices of low carbon development of agriculture were put forward. The results of this study could provide scientific basis for making carbon-reduction policy and sustainable development of agriculture in Gansu province.

Key words: agricultural carbon emission, LMDI model, influential factors, Gansu Province