Abstract: After acetochlor was mixed with calcium chloride and sodium dodecyl sulfate (SDS) solution,acetochlor calcium carbonate microsphere formulation was prepared by making sodium carbonate react upon the mixture.The microsphere formulation was then characterized by SEM,particle size distribution and HPLC,and its preparation process,loading efficiency and release properties were studied.The results showed that the crystal structure of calcium carbonate carriers belonged to calcite structure;with n (CaCl2):n(Na2CO3):n(SDS) as 1:2:2,and stirring speed of 500 r/min,stirring time of 10 min,the loading rate was nearly 20% and loss rate was 0.2% in room temperature.Simultaneously,the surface was spherical with narrow size distribution,which was normal distribution;the release rate of acetochlor from the microsphere formulation increased as the temperature and pH value increased.The results of present study would provide useful information for further investigation and application of timing and quantitative field release of pesticide in the future.