Abstract: A kind of microcapsule was researched and applied to improve the breathability of the coated fabric.In-Situ Limited Coalescence Polymerization was employed to prepared microcapsules,using MMA as wall material and water as core.The processing parameters in the preparation were optimized by the orthogonal design method.The influence of several factors,including shell materials,emulsifier initiator etc,on the microcapsule′s size,size distribution and other performances were discussed.Then the microcapsules were mixed with the finishing agents and applied in the coating experiment.The result showed that the breathability of the coated fabric was improved to a certain extent.