A novel ultra-rapidly curable one-pack system was designed, where micro-coated isocyanate particle and liquid amine were combined. In this system, its main curing reaction is based on the nucleophilic polyaddition between diisocyanates and di- or tri-functional amines which results in the formation of urea linkage. When micro-coated 4,4ʼ-Diphenylmethane diisocyanate（ MDI） was used, the viscosity of mixture with amine hardly increased up to 5 weeks at 5℃ while it rose to 5 times after 5-day storage at 25℃. The measurement of gel-time on the hot plate revealed that this type of thermosetting resin can be cured in an extremely short time like 25 s at 40℃ or 0.5 s at 160℃. The bond strength of this resin measured by tensile shear test using aluminum plates broadly varied from 8 to 26 MPa depending on curing temperature. When cured at a lower temperature, it seemed very difficult for such rapidly curable isocyanate moiety to well-diffuse in the sea of amine in the heterogeneous system, which led to the low bond strength. On the other hand, it is considered that the cause that bond strength reached 25 MPa or more when cured at 200℃ is related to dissociation of urea linkage and subsequent complete diffusion of free isocyanate and amine.