Microcapsule suspensions containing photoactivatable compound 2,5-diphenylethynylthiophene were prepared by interfacial polymerization with trimer of isophorone diisocyanate and diethylenetriamine.The surface morphology and diameter of microcapsules were studied by scanning electron microscopy and fluorescence optical microscopy.The release characterization,preliminary microencapsulated efficiency,thermal stability and bioactivity of the microcapsules were investigated.The results showed that microcapsules were spherical,the preliminary microencapsulated efficiency were higher than 90%.Comparing with the 2,5-diphenylethynylthiophene,the microcapsule showed good bioactivity to the second-instar larvae of pieris rapae,but more importantly,the lasting period was extended.