Abstract: The present invention relates to a novel catalyst for producing N-substituted carbamates, the preparation of the catalyst and an improved method for producing N-substituted carbamates from these novel catalysts. The active component of the catalyst is a heteropoly acid and the catalyst support comprises a metal oxide or a metalloid oxide. The catalyst can be used to promote the reaction of carbamate and amine, thereby generating N-substituted carbamates with high yield. In the presence of the catalyst, the reaction conditions are relatively mild, the catalytic activity and selectivity of the reaction are high, and the reaction time is relatively short. Furthermore, the catalyst can be conveniently separated from the reaction system and recycled, therefore, the catalyst can be used to facilitate the further scale-up test and commercial application.