Agricultural PM₁₀ and PM_2.5 inventories on the county-level scale in northeastern China were developed in this study. Based on bottom-Up method, we firstly collect the agricultural activity data, including conventional farming operations (i.e., straw burning, land preparation, harvest, grain processing, fertilizer, agricultural machinery, and wind erosion), emission factors of these operations and crop area at each county. And then, county-level PM₁₀and PM_2.5 emission inventories from agricultural operations in 2010 were developed and spatio-temporal distributions were analyzed. The results showed that the magnitude of agricultural PM₁₀ and PM_2.5 emissions in northeastern China were 54.6×10⁴ tons and 35.6×10⁴ tons, respectively. The PM₁₀ and PM_2.5 emissions from straw burning were highest, which accounted for 60% and 87% of the total emissions, respectively. In addition, land preparing occupied 27% and 6% for PM₁₀ and PM_2.5, respectively. The spatial distribution of agricultural PM emissions, concentrated on three plains, i.e., the Sanjiang Plain (in the northeast of Heilongjiang), the Songnen Plain (in the middle of Heilongjiang and Jilin Provinces), the Liaohe Plain (in the middle of Liaoning Provinces). Based on temporal variations, agricultural PM₁₀ emissions mainly occurred in May, September and October, which contributed 88% of total emissions. The PM_2.5 was mainly released in September and October. The uncertainty of emission inventory was 184.3%. More information on local emission factors will be helpful to decrease the emission inventory uncertainty.