To provide a one-solution-moisture-curing type of a polyurethane sealing material having excellent workability, a good internal curing property and a material property.

A polyurethane sealing material contains a synthetic material wherein a silicon compound (A) having a secondary amino group or a hydroxy group of less than two is synthesized by reacting an alkoxysilane having a primary amino group, a secondary amino group, a methacryloyl group, an epoxy group or a mercapto group and having two alkoxy groups with methacrylate or the like, and an urethane prepolymer (B) is synthesized by reacting a polyol with a polyisocyanate compound, obtaining by further reacting A with B in a ratio of less than 0.5 equivalent to an NCO group of B.